Biotoxicity of mercury to Chlorella vulgaris as influenced by amino acids.

Mohapatra DK, Mohanty L, Mohanty RC, Mohapatra PK.

Department of Botany, Uktal University, Bhubaneswar, India.

The toxicity of mercury ion, on Chlorella vulgaris, is largely influenced by amino acids. Five amino acids, namely alanine, asparagine, glutamic acid, cysteine and histidine, were added separately to the medium containing static dose of mercury. Survival (%) of the alga was reduced with the increasing concentrations of mercury. Of these five amino acids, cysteine was found to be the most effective while alanine and glutamic acid were the least effective on reducing the toxic effect of mercury on the alga measured in terms of growth, chlorophyll and protein content. The order of detoxification was Alanine < Glutamate < Asparargine < Histidine < Cysteine. Amino acids from ligands with Hg2+ making it less toxic to the alga and produce an additional source of energy for growth and development.

PMID: 9847462 [PubMed - indexed for MEDLINE]

Change in toxicity effect of mercury at static concentration to Chlorella vulgaris with addition of organic carbon sources.

Mohanty RC, Mohanty L, Mohapatra PK.

Department of Botany, Utkal University, Bhubaneswar, India.

The effect of mercury on Chlorella vulgaris is influenced to a large extent by organic carbon sources like glucose, glutamate, and 2-oxoglutarate which is exhibited through changes in growth and metabolic processes of the alga in the presence of static dose (0.200 +/- 0.004, p = 0.05) of Hg2+. Addition of the three carbon sources to the Hg(2+)-amended Chu No 10+ medium resulted in an acceleration of pigment biomass, growth, and protein content of the green alga. Glucose at all concentrations was found to be more effective than the other two in reducing the mercury toxicity to C. vulgaris. However, the detoxifying effect is dependent on the type of carbon sources, their concentration and days of incubation. Glucose at 5 mg/l significantly reduced Hg2+ toxicity while glutamate and 2-oxoglutarate, at this concentration, did not show such capacity. Similarly the degree of significance of ameliorative effect increased with increase in incubation period which, however, varied with the carbon source. Availability of additional energy and formation of non-toxic or less toxic mercury are the probable causes of reduction in toxicity effects.

PMID: 7910427 [PubMed - indexed for MEDLINE]

Attached algal flora in the rivers receiving effluent from copper mines in Japan.

Yasuno M, Fukushima S.

National Institute for Environment Studies, Tsukuba, Japan.

PMID: 3448856 [PubMed - indexed for MEDLINE]

Influence of selenium on toxicity of some heavy metals in the green alga Scenedesmus obliquus.

Issa AA, Adam MS.

Botany Department, Faculty of Science, Assiut University, Egypt.

The green alga Scenedesmus obliquus was incubated with various heavy metals (Cd2+, Zn2+, Mn2+, Ni2+) in presence/absence of selenium. S. obliquus exhibited higher rates of growth and some metabolic activities in cultures containing 0.1 mM Se than those containing only the heavy metals. The positive effect of Se was found in presence of Cd2+ while that in the case of presence of Ni2+ was less pronounced.

PMID: 10756714 [PubMed - indexed for MEDLINE]

Cadmium toxicity to green alga Stichococcus bacillaris.

Skowronski T, Jakubowski M, Pawlik B.

PMID: 2421548 [PubMed - indexed for MEDLINE]

Toxicity of nickel to microbes: environmental aspects.

Babich H, Stotzky G.

PMID: 6650263 [PubMed - indexed for MEDLINE]

Effects of cadmium on the biota: influence of environmental factors.

Babich H, Stotzky G.

Publication Types:

Review

PMID: 210637 [PubMed - indexed for MEDLINE]

Biological effects of heavy metal pollutants in water.

Hartung R.

PMID: 4769158 [PubMed - indexed for MEDLINE]

Study of the environmental hazard caused by the oil shale industry solid waste.

Pollumaa L, Maloveryan A, Trapido M, Sillak H, Kahru A.

National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, Estonia.

The environmental hazard was studied of eight soil and solid waste samples originating from a region of Estonia heavily polluted by the oil shale industry. The samples were contaminated mainly with oil products (up to 7231mg/kg) and polycyclic aromatic hydrocarbons (PAHs; up to 434mg/kg). Concentrations of heavy metals and water-extractable phenols were low. The toxicities of the aqueous extracts of solid-phase samples were evaluated by using a battery of Toxkit tests (involving crustaceans, protozoa, rotifers and algae). Waste rock and fresh semi-coke were classified as of "high acute toxic hazard", whereas aged semi-coke and most of the polluted soils were classified as of "acute toxic hazard". Analysis of the soil slurries by using the photobacterial solid-phase flash assay showed the presence of particle-bound toxicity in most samples. In the case of four samples out of the eight, chemical and toxicological evaluations both showed that the levels of PAHs, oil products or both exceeded their respective permitted limit values for the living zone (20mg PAHs/kg and 500mg oil products/kg); the toxicity tests showed a toxic hazard. However, in the case of three samples, the chemical and toxicological hazard predictions differed markedly: polluted soil from the Erra River bank contained 2334mg oil/kg, but did not show any water-extractable toxicity. In contrast, spent rock and aged semi-coke that contained none of the pollutants in hazardous concentrations, showed adverse effects in toxicity tests. The environmental hazard of solid waste deposits from the oil shale industry needs further assessment.

PMID: 11387023 [PubMed - indexed for MEDLINE]

[Determination of various toxic minerals in spiruline algae of different origins, and evaluation of long-term toxicity in the rat of a lot of spiruline algae of Mexican origin]

[Article in French]

Boudene C, Collas E, Jenkins C.

A detailed analytical study made on samples of Spirulines algae of various origins showed that these microorganisms may present an important telluric contamination, especially demonstrated by high levels of fluorine and arsenic they contain. A long term animal experimentation has been achieved with Spirula Maxima, obtained from the Sosa Texcoco solar evaporator. A diet contained in total proteins 25 p. 100 of dried atomized algae and was given for 75 weeks to Wistar rats. All along the experiment, the animals submitted to that diet showed no difference with control animals fed with caseine. The increase in weight was comparable for control animals and male experimented animals; a slight decrease in weight has been observed for females fed with algae up to the 30th week. At the end of the experiment, a normal frequency of tumours was noted on experimented animals. The cumulative potentiality of certain mineral toxicants, has been evaluated, when abnormal high levels of them have been detected in the Spirulines samples. The fed animals have been killed at definite times all along the experiment and the metals dosed in the body. Such a cumulative potency has been demonstrated for arsenic. On the contrary, in the case of fluorine, even particular dosages in the femoral bone could not show any significant cumulation of that toxicant, comparing with control animals. In conclusion, the authors have not noted any evident toxicity related to the samples of Spirulines tested in rats, whatever these algae were the only source of proteins in the diet. They hope anyway that the exact origin of contamination of these algaes by these metals will be better known to prevent the variations in the composition of industrial samples of Spirulines according to these metals for instance.

PMID: 825000 [PubMed - indexed for MEDLINE]

Effects of temperature on cadmium toxicity to the green alga Scenedesmus acutus. I. Development of cadmium tolerance in batch cultures.

ten Hoopen HJ, Nobel PJ, Schaap A, Fuchs A, Roels JA.

PMID: 4091538 [PubMed - indexed for MEDLINE]

Effects of temperature on cadmium toxicity to the green alga Scenedesmus acutus. II. Light-limited growth in continuous culture.

van Gemert JM, ten Hoopen HJ, Roels JA, Fuchs A.

PMID: 4091539 [PubMed - indexed for MEDLINE]

Effect of sublethal concentrations of four chemicals on susceptibility of juvenile rainbow trout (Oncorhynchus mykiss) to saprolegniosis.

Carballo M, Munoz MJ.

Department of Animal Health, CIT-I.N.I.A., Madrid, Spain.

The effects of sublethal concentrations of a variety of chemicals on the susceptibility of rainbow trout (Oncorhynchus mykiss) juveniles to Saprolegnia parasitica infection was examined. Sublethal concentrations of un-ionized ammonia (0.05 mg/liter) and nitrite (0.12 mg/liter) increased fish susceptibility after 10 days of exposure to the toxin, this increase being higher for ammonia (75% and 20% morbidity) than for nitrite (20% and 0% morbidity, respectively) with inoculum doses of 1.4 x 10(6) and 9.5 x 10(5) zoospores per liter, respectively. Sublethal concentrations of copper (0.05 mg/liter) or cyanide (0.05 mg/liter) did not show enhancement of infection by S. parasitica, even though the toxin exposure was for 21 days and the inoculum doses were higher than those for the experiments with the nitrogen compounds (4 x 10(6) and 3.2 x 10(6) zoospores per liter. However, infections began to appear in control animals.

PMID: 1872610 [PubMed - indexed for MEDLINE]

Isolation and genetic analysis of Chlamydomonas reinhardtii strains resistant to cadmium.

Collard JM, Matagne RF.

Laboratoire de Genetique des Microorganismes, Universite de Liege, Belgium.

In Chlamydomonas reinhardtii, cadmium induces reduction of growth, reduction of chlorophyll content, and lethality. The toxicity was higher in a cell wall-deficient strain than in the wild type. By growing the cells on agar medium containing cadmium at concentrations inducing high lethality, stable resistant clones were isolated. The resistance was due to a nuclear mutation (cadAR) which probably preexisted in the wild-type cell population, as suggested by the fluctuation test. A double mutant (cadAR cadBR) was selected on media containing higher concentrations of cadmium. The cadBR mutation, which is unlinked to cadAR, determines a resistance intermediate between the CadAR mutant and the wild-type strain. Both cadAR and cadBR mutations are partially dominant.

PMID: 2389932 [PubMed - indexed for MEDLINE]

Variation in the toxicity of arsenic compounds to microorganisms and the suppression of the inhibitory effects by phosphate.

Da Costa EW.

PMID: 5062093 [PubMed - indexed for MEDLINE]

Interactions of algal ligands, metal complexation and availability, and cell responses of the diatom Ditylum brightwellii with a gradual increase in copper.

Rijstenbil JW, Gerringa LJ.

NIOO-CEMO, Netherlands Institute of Ecology, Centre for Estuarine and Coastal Ecology, P.O. Box 140, NL-4400 AC NL, Yerseke, Netherlands. [email protected]

A continuous culture experiment was conducted to study interactions between copper-binding ligands released by light-limited Ditylum brightwellii, and toxic effects of Cu on this diatom. Over 6 months, the Cu concentration in the medium has been increased in seven steps (3-173 nM). At each Cu addition, Cu speciation, characteristics of Cu sorption to cellular binding sites, and cell characteristics were determined. Physiological effects of Cu were studied, using indicators for metal detoxification (thiols) and lipid peroxidation (malondialdehyde). Minor amounts of Cu (<1.4%) were chelated by a minimum amount of EDTA (57 nM), required to maintain a stable long-term continuous culture. The responses of D. brightwellii to Cu were monitored. (1) From 3 to 47 nM added Cu, decreasing pools of glutathione, increasing malondialdehyde contents, an increased release of lipophilic ligands, and cell lysis indicated the enhancement of lipid peroxidation. (2) From 47 to 94 nM Cu, a 16-fold increase in high-affinity (strong) hydrophilic ligands was measured (conditional stability constants K' approximately 10(12)) that complexed most Cu (maximum 97%); sexual reproduction was stimulated and cell volumes increased. (3) From 126 nM Cu, glutathione pools increased again, whereas cell division rates decreased slightly. (4) At 142 nM Cu, the number of lysed cells reached a maximum, as did the production of lipophilic compounds that complexed approximately 2% Cu. As the binding sites of the strong ligands became Cu-saturated above 142 nM Cu, larger amounts of Cu were bound to low-affinity (weak) dissolved ligands (3-30%) and cellular binding sites (0.2-2.5%). Probably due to saturation of organic complexes at 142 nM Cu, the MINEQL-calculated Cu2+ concentrations increased markedly; pCu values decreased from >11 to approximately 10; division rates were further inhibited; gamma-glutamylcysteine (phytochelatin precursor) was produced. (5) At 157 nM Cu, phytochelatin synthesis started, and Cu-sorption capacities (cell walls and internal binding sites) increased. (6) At 173 nM Cu, the phytochelatin pool sizes and the number of cellular Cu-binding sites increased further. These results suggest that ligands released by a dense bloom of D. brightwellii, either by active excretion or lysis, would have lower affinities for Cu (K' approximately 10(9)-10(12)) and moderate the availability of Cu less effectively than ligands in natural environments (10(13)-10(14)). In this diatom, the concurring release of ligands, enhanced malondialdehyde production, increasing numbers of presexual cells and cell enlargement may serve as early-warning signals for Cu toxicity, rather than metal-specific phytochelatins that appeared at a stage when cell division was already clearly inhibited.

PMID: 11755700 [PubMed - indexed for MEDLINE]

Effects of zinc on the phosphorus availability to periphyton communities from the river Gota Alv.

Paulsson M, Mansson V, Blanck H.

Department of Plant Physiology, Goteborg University, Box 461, 405 30 Goteborg, Sweden.

It has been hypothesised that zinc additions in the phosphorus limited (12-15 microg l(-1)) River Gota Alv leads to an interaction between zinc and phosphate which causes a decreased availability of phosphate and a concomitant decrease in biomass production in the Gota Alv periphyton communities 'Aquat. Tox. 47 (2000) 243'. To test the hypothesis the experiment by Paulsson et al. 'Aquat. Tox. 47 (2000) 243' was repeated, now with focus on phosphorus status of the periphyton. Additional indicators of phosphorus deficiency, e.g. alkaline phosphatase activity (APA), surplus and total phosphorus, intracellular acid phosphatase activity, and nitrogen and carbon were measured in the communities. APA increased and surplus phosphorus decreased at about the same zinc exposure concentration as the dry weight started to decrease (> 0.1 microM), thus supporting the hypothesis of a zinc-induced phosphorus deficiency. Nitrogen and carbon concentrations in the biofilm also decreased with increasing zinc exposure, suggesting an influence on metabolism of these elements as well. It can be concluded that zinc might be an environmental hazard in phosphorus-limited environments at concentrations above 0.1-0.2 microM of total zinc.

PMID: 11755699 [PubMed - indexed for MEDLINE]

Phytochelatin production in freshwater algae Stigeoclonium in response to heavy metals contained in mining water; effects of some environmental factors.

Pawlik-Skowronska B.

Institute of Ecology, Polish Academy of Sciences, Experimental Station, Niecala 18/3, 20-080, Lublin, Poland. [email protected]

Production of phytochelatins (PC) in two freshwater, filamentous green algae of the genus Stigeoclonium, in response to heavy metals contained in mining water was studied. Stigeoclonium sp. grown abundantly in ditches with the mining water (southern Poland) accumulated high amounts of heavy metals. The other studied alga Stigeoclonium tenue Kutz. was isolated from unpolluted lake water in the Netherlands. Both algae exposed to the heavy metal mixture (17 microM; mainly zinc) contained in the hard, alkaline (pH 8.2) mining water produced similar amounts of phytochelatins (PC2 and PC3): 500-600 nmol SH g(-1) dry weight. After water acidification to pH 6.8, a > 2-fold increase of the total phytochelatin level as well as the appearance of longer chain peptide PC4 in the cells of both algae was observed. The concentration of labile forms of zinc in the acidified mining water was four times as high as that in the alkaline water. The heavy metal mixture (17 microM) in non-complexing solution of pH 6.8 caused a comparable phytochelatin production in both Stigeoclonium strains as the same mixture present in the acidified mining water. However, in the non-complexing solution of pH 8.2, the metal mixture induced in algae more PCs than at pH 6.8. A positive effect of bicarbonate enrichment in the solution on the PC production in S. tenue was also observed. Stigeoclonium sp. exposed to high concentrations (10 microM) of individual metals (Zn, Pb and Cd available as free cations) synthesised much higher amounts of phytochelatins (PC2-PC4) than in response to the metal mixture contained in the mining water. The order of PC induction by the studied metals in the Stigeoclonium sp. was Cd > Pb > Zn. Addition of suspended solid matter to the heavy metal solution resulted in essential quantitative changes in phytochelatins in algal cells; a considerable decrease of PC2, PC3 and PC4 levels was observed. The PC production in algae of the genus Stigeoclonium exposed to the heavy metal mixture is discussed in the context of various metal bioavailability and the algal adaptation to complex aquatic environment.

PMID: 11239685 [PubMed - indexed for MEDLINE]

Effects of Al(3+) ions and Cu(2+) ions on microcosms with three different biological complexities.

Sugiura K.

Sagami Women's University, 2-1-1 Bunkyo, Sagamihara-shi, 228-8533, Kanagawa, Japan. [email protected]

Cu(2+) ions or Al(3+) ions were added to microcosms containing three, four and eight species (S-3, S-4, S-8) at the beginning of the culture, or at the 15th day from the beginning of the culture to determine the production rates (P), the respiration rates (R), and P/R ratios. There was a balance between the oxygen production rates and the oxygen consumption rates in the microcosms (S-4) and (S-8), whereas there was no balance between two quantities in the microcosm (S-3). There were no significant differences in the Cu(2+) and Al(3+) ion concentrations influencing the material cycles and the metabolic balance between the case when the number of species was four and the case when the number of species was eight. It was assumed that the effects concentrations of the chemical substances are not significantly related to the degree of diversity of the constituent species in the microcosms having a balance between production and consumption.

PMID: 11090899 [PubMed - indexed for MEDLINE]

Hsp70 expression in Enteromorpha intestinalis (Chlorophyta) exposed to environmental stressors.

Lewis S, Donkin ME, Depledge MH.

Wessex Human Genetics Institute, Duthie Building, Tremona Road, SO16 6YD, Southampton, UK. [email protected]

Numerous studies have indicated that stress proteins have potential as biomarkers of exposure to environmental contaminants. Analysis of stress proteins in animals, especially Hsp70, has dominated this research area despite increasing interest in the use of plants as pollution monitors. In the present study Hsp70 expression in Enteromorpha intestinalis has been investigated under exposure to a variety of stressors, to evaluate the potential use of Hsp70 as a biomarker of contaminant exposure in this seaweed. E. intestinalis was exposed to thermal stress, copper under differing conditions of nutrient availability and the triazine herbicide Irgarol 1051. Measurements were also taken to compare Hsp70 with conventional sublethal endpoints of toxicity such as growth and fluorescence induction parameters such as Fv/Fm. E. intestinalis exhibited a typical heat shock response. Hsp70 expression was increased with copper exposure, but proved to be a relatively insensitive biomarker of copper exposure compared to growth measurements. Nutrient limitation enhanced copper toxicity and significantly impaired growth, Fv/Fm and Hsp70 production. Fv/Fm and growth were strongly affected by Irgarol 1051 exposure, but Hsp70 levels were unaltered following exposure to the herbicide. The implications of using Hsp70 expression in E. intestinalis as a biomarker are discussed.

PMID: 11090890 [PubMed - indexed for MEDLINE]

Relationships between acid-soluble thiol peptides and accumulated Pb in the green alga Stichococcus bacillaris.

Pawlik-Skowro&nacute;ska B.

Institute of Ecology, Polish Academy of Sciences, Experimental Station, Niecala 18/3, 20-080, Lublin, Poland

Stichococcus bacillaris, an ubiquitous green microalga accumulated inorganic lead (Pb) from aqueous solutions extra- and intracellularly. In response to Pb uptake acid-soluble thiol peptides (glutathione - GSH and phytochelatins - PC) were synthesized. The proportion of the intracellular Pb uptake by algal cells was low and comprised only 3-6% of the total metal sorption. The intracellular uptake was dependent on external Pb concentration, time of metal exposure and cell metabolism. Pb accumulation in alga was determined by means of 210Pb radiometry. Reduced GSH and PC were determined in algal cells using HPLC with the post-column derivatization with Ellman's reagent. Within the studied concentration range 0.1-20 microM, inorganic lead caused a significant production of induced thiol peptides: PC (n=2-4) and some other unidentified oligopeptides, probably (GluCys)n. The time of appearance and the concentration of individual oligomers of phytochelatins were dependent on the external Pb concentration and time of metal exposure. In algal cells exposed to Pb, significant changes in the GSH level accompanying the formation of the induced thiol peptides were also observed. The GSH level decreased in the cells exposed to the lower (up to 10 microM) studied Pb concentrations or increased in the cells treated with higher (20 microM) Pb concentrations. The thiol groups originated from induced peptides (mainly phytochelatins) followed a stoichiometric relationship 2:1 to the intracellular Pb amounts, however, only at the lowest studied external concentration (0.1 microM). At higher concentrations (up to 2.5 microM), intracellular Pb concentration was equal or even exceeded (at Pb>2.5 microM) two to three times the level of induced thiols. S. bacillaris accumulated intracellularly by 46% more Pb in light than in dark and the level of induced thiol peptides was significantly higher in the cells exposed to Pb under illumination. The rapid formation of these peptides in S. bacillaris in response to Pb, and their elimination (by about 90%) when algae were placed into the Pb-free solution reveal a tight regulation of GSH and phytochelatin pools in the algal cells exposed to toxic metals. The obtained results suggest that both PCs and GSH are the primary line of defence against the Pb toxicity. Additionally, the induced thiol peptides in S. bacillaris could be a good indicator of intracellular Pb availability and stress at the metal concentrations found in polluted fresh waters.

PMID: 10958956 [PubMed - as supplied by publisher]

pH-dependent toxicity of copper and uranium to a tropical freshwater alga (Chlorella sp.).

Franklin NM, Stauber JL, Markich SJ, Lim RP.

Centre for Advanced Analytical Chemistry, CSIRO Energy Technology, PMB 7, Bangor, Australia

Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical freshwater organisms in northern Australia as a result of mining activity. No local data on the toxicity of these metals to tropical freshwater algae are currently available. The aim of this study was to investigate the effect of pH (5.7 and 6.5) on the toxicity of Cu and U to the green alga Chlorella sp. in a synthetic softwater representative of fresh surface waters in sandy-streams of tropical northern Australia. The effects of Cu and U on algal growth (cell division) rate after a 72-h exposure were determined. Intracellular and extracellular (membrane-bound) metal concentrations at the two selected pH values were also compared. Based on the 72-h minimum detectable effect concentrations (MDEC), Chlorella sp. was approximately 20-fold more sensitive to Cu (0.7 and 1.4 microg l(-1) at pH 6.5 and 5.7, respectively) than U (13 and 34 microg l(-1) at pH 6.5 and 5.7, respectively), and more sensitive than other Australian tropical freshwater organisms. The toxicity of Cu and U was highly pH-dependent. Copper concentrations required to inhibit growth (cell division) rate by 50% (72-h EC(50)) increased from 1.5 to 35 microg l(-1) as the pH decreased from 6.5 to 5.7. Similarly, the 72-h EC(50) values for U increased from 44 to 78 microg l(-1) over the same pH range. Calculation of Cu and U speciation using the geochemical model HARPHRQ, showed that differences in the concentrations of the free metal ions (Cu(2+) and UO(2)(2+)) were only minimal (<10%) between pH 5.7 and 6.5. The decreased toxicity at pH 5.7 was due to lower concentrations of cell-bound and intracellular Cu and U compared to those at pH 6.5. These results are explained in terms of the possible mechanism of competition between H(+) and the metal ion at the cell surface.

PMID: 10686332 [PubMed - as supplied by publisher]

PAM fluorometry in the determination of the sensitivity of Chlorella vulgaris, Selenastrum capricornutum, and Chlamydomonas reinhardtii to copper.

Juneau P, El Berdey A, Popovic R.

Universite du Quebec a Montreal, Chemistry-Biochemistry Department/TOXEN, C.P.8888, Succ. Centre-Ville, Montreal, Quebec, Canada.

The pulse-amplitude-modulation (PAM) fluorometric method was used in the past as a sensitive and rapid method for assessing toxic effect of pollutants in plants. Here, we used the advantages of this method to evaluate the difference in sensitivity of Chlorella vulgaris, Selenastrum capricornutum, and Chlamydomonas reinhardtii to copper toxicity. We found by using the PAM-fluorescence parameters (phiM, phi'M, QP, and QN), that C. reinhardtii is the most sensitive species, followed by S. capricornutum and C. vulgaris. Indeed, the copper 5-, 48-, and 96-h EC50 for phiM, phi'M, and QP vary between 11 and 34 microg/L for C. reinhardtii, while for S. capricornutum this value is between 25 and 50 microg/L. However, the same parameters obtained from C. vulgaris did not show susceptibility to copper, even at very high concentrations (100 microg/L). In this study, the estimated 5-h EC50 for C. reinhardtii and S. capricornutum are lower than the 24-h EC50 reported earlier for these species with other bioassays, indicating that the use of PAM fluorometry in copper bioassay provides a more sensitive method than the other biotests in aquatic toxicology.

PMID: 11815806 [PubMed - indexed for MEDLINE]

A 48-h larval development toxicity test using the marine polychaete Galeolaria caespitosa Lamarck (Fam. Serpulidae).

Ross KE, Bidwell JR.

School of Pharmacy and Medical Sciences, University of South Australia, North Terrace, Adelaide, Australia.

Assessing the risk of effluents and other anthropogenic inputs to the receiving environment is ultimately best done on a site-specific basis, which often requires toxicity tests using organisms relevant to that environment. Additionally, the test species or life stage needs to be available for a reasonable portion of the year to allow temporal fluctuations to be assessed. A 48-h larval development toxicity test using the marine polychaete Galeolaria caespitosa was developed. This test was developed as G. caespitosa releases viable gametes year-round, and the test species is environmentally relevant to the marine system receiving the liquid effluent being evaluated. Toxicity tests were conducted using G. caespitosa from different locations and evaluating the gamete response to copper. All population responses were comparable, with EC50 values ranging from 16 to 40 microg/L copper (as CuCl2, x 2H2O). Toxicity tests were also conducted using G. caespitosa gametes with an effluent produced by a lead smelting operation. The response of the G. caespitosa test with this effluent was compared with three other test methods using two microalgal species, Isochrysis sp. and Nitzschia closterium, and gametes from the mussel Mytilus edulis. The G. caespitosa larval development toxicity test was the most sensitive test to the effluent, with EC50 values ranging from 1-23% effluent, while it ranked second in sensitivity to copper. This test could be applied to other common serpulids worldwide.

PMID: 11525491 [PubMed - indexed for MEDLINE]

Development of an improved rapid enzyme inhibition bioassay with marine and freshwater microalgae using flow cytometry.

Franklin NM, Adams MS, Stauber JL, Lim RP.

Centre for Advanced Analytical Chemistry, CSIRO Energy Technology, Bangor, New South Wales, Australia. [email protected]

A rapid toxicity test based on inhibition of esterase activity in marine and freshwater microalgae (Selenastrum capricornutum, Chlorella sp., Dunaliella tertiolecta, Phaeodactylum tricornutum, Tetraselmis sp., Entomoneis cf. punctulata, Nitzschia cf. paleacea) was developed using flow cytometry. Uptake of fluorescein diacetate (FDA) was optimized for each species by varying the substrate concentration, incubation time, and media pH. Propidium iodide (PI) was utilized to assess membrane integrity. The optimized FDA/PI staining procedure was then used to assess the toxicity of copper in short-term exposures (1-24 h). Esterase activity was a sensitive indicator of copper toxicity in S. capricornutum and E. cf. punctulata. As copper concentrations increased, esterase activity decreased in a concentration-dependent manner. The 3- and 24-h EC50 values (based on mean activity states) were 112 microg Cu L(-1) (95% confidence limits 88-143) and 51 microg Cu L(-1) (95% confidence limits 38-70) for S. capricornutum and 47 microg Cu L(-1) (95% confidence limits 43-51) and 9.1 microg Cu L(-1) (95% confidence limits 7.6-11) for E. cf. punctulata, respectively. This enzyme inhibition endpoint showed similar sensitivity to chronic growth rate inhibition in E. cf. punctulata (48-h and 72-h EC50 values of 17 and 18 microg L(-1), respectively) but was less sensitive compared to growth for S. capricornutum (48-h and 72-h EC50 values of 4.9 and 7.5 microg L(-1), respectively). For the other five species tested, inhibition of FDA fluorescence was relatively insensitive to copper, even at copper concentrations that severely inhibited cell division rate. These short-term bioassays that detect sublethal endpoints may provide a more rapid and cost-effective way of monitoring contaminant impacts in natural waters.

PMID: 11525489 [PubMed - indexed for MEDLINE]

Antioxidant modulation in response to metal-induced oxidative stress in algal chloroplasts.

Okamoto OK, Pinto E, Latorre LR, Bechara EJ, Colepicolo P.

Dept. Bioquimica, Instituto de Quimica, Universidade de Sao Paulo, C.P. 26077 05599-970, Sao Paulo, SP, Brazil.

To investigate adaptive responses to metal stress at the subcellular level, the oxidative balance in isolated chloroplasts was evaluated for the first time in the unicellular alga Gonyaulax polyedra exposed to the toxic metals Hg(2+), Cd(2+), Pb(2+), and Cu(2+). Different antioxidant responses were verified according to the metal and model of stress applied. Cells chronically exposed to metals exhibited high activity of the antioxidant enzymes superoxide dismutase and ascorbate peroxidase, high glutathione content, and decrease of peridinin levels, whereas no significant changes were detected for beta-carotene levels. In contrast, cells subjected to acute metal stress displayed twice as much beta-carotene but only a slight increase in superoxide dismutase and ascorbate peroxidase activities. The correlation of acute metal treatment and oxidative stress was inferred from the higher oxygen uptake and decreased reduced glutathione pool found in treated cells. In addition, increased oxidative damage to proteins and lipids occurred mainly in cells under acute stress. Pb(2+) was the most damaging toxicant, causing protein oxidation and lipid peroxidation even at chronic treatment. These results indicate that heavy metals are able to induce oxidative stress in chloroplasts of G. polyedra, particularly under acute conditions. Nevertheless, the maintenance of a high antioxidant capacity within chloroplasts seems to be an important strategy during acclimation of G. polyedra to chronic metal stress. By acting at the subcellular site, where oxidative stress is triggered, induction of such chloroplast antioxidants might be crucial for cell survival during exposure to heavy metals.

PMID: 11116337 [PubMed - indexed for MEDLINE]

Bioavailability of metals in stream food webs and hazards to brook trout (Salvelinus fontinalis) in the upper Animas River watershed, Colorado.

Besser JM, Brumbaugh WG, May TW, Church SE, Kimball BA.

U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201, USA.

The water quality, habitats, and biota of streams in the upper Animas River watershed of Colorado, USA, are affected by metal contamination associated with acid drainage. We determined metal concentrations in components of the food web of the Animas River and its tributaries-periphyton (aufwuchs), benthic invertebrates, and livers of brook trout (Salvelinus fontinalis)-and evaluated pathways of metal exposure and hazards of metal toxicity to stream biota. Concentrations of the toxic metals cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in periphyton, benthic invertebrates, and trout livers from one or more sites in the upper Animas River were significantly greater than those from reference sites. Periphyton from sites downstream from mixing zones of acid and neutral waters had elevated concentrations of aluminum (Al) and iron (Fe) reflecting deposition of colloidal Fe and Al oxides, and reduced algal biomass. Metal concentrations in benthic invertebrates reflected differences in feeding habits and body size among taxa, with greatest concentrations of Zn, Cu, and Cd in the small mayfly Rhithrogena, which feeds on periphyton, and greatest concentrations of Pb in the small stonefly Zapada, a detritivore. Concentrations of Zn and Pb decreased across each trophic linkage, whereas concentrations of Cu and Cd were similar across several trophic levels, suggesting that Cu and Cd were more efficiently transferred via dietary exposure. Concentrations of Cu in invertebrates and trout livers were more closely associated with impacts on trout populations and invertebrate communities than were concentrations of Zn, Cd, or Pb. Copper concentrations in livers of brook trout from the upper Animas River were substantially greater than background concentrations and approached levels associated with reduced brook trout populations in field studies and with toxic effects on other salmonids in laboratory studies. These results indicate that bioaccumulation and transfer of metals in stream food webs are significant components of metal exposure for stream biota of the upper Animas River watershed and suggest that chronic toxicity of Cu is an important factor limiting the distribution and abundance of brook trout populations in the watershed.

PMID: 11116340 [PubMed - indexed for MEDLINE]

Reclamation of wastewater for polyculture of freshwater fish: bioassays using Chlorella and Gambusia.

Liang Y, Wong MH.

Institute for Natural Resources and Waste Management and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong, P. R. China.

The feasibility of using the secondary effluents from two sewage treatment plants in Hong Kong (Yuen Long and Shek Wu Hui) for fish culture was assessed. Total ammonia contents in the two sewage effluents surpassed the level of 2 mg L(-1) recommended for wastewater fish culture. The two sewage effluents both needed essential elements for supporting algal Chlorella vulgaris growth, whereas only sewage effluent from Yuen Long had contaminants at toxic levels. Total ammonia in water explained more than 80% variations of toxicity of water samples to Gambusia patruelis, mosquito fish, according to regression analysis. Removal of ammonia from the sewage effluent is necessary before being used for fish culture. In addition, the rather high levels of heavy metals (Cu, Zn, Cd) in the effluent should be closely monitored.

PMID: 11031312 [PubMed - indexed for MEDLINE]

Ecotoxicity of contaminated suspended solids for filter feeders (Daphnia magna).

Weltens R, Goossens R, Van Puymbroeck S.

VITO-Flemish Institute for Technological Research, Department of Environmental Toxicology, Boeretang 200, B2400 MOL, Belgium.

It is generally assumed that the dissolved fraction of a toxic substance in surface water is mainly responsible for toxicity to aquatic organisms. However, toxic compounds are often adsorbed or chemically bound to suspended particles in the water column, depending upon the physico-chemical conditions. In the present study potential adverse effects to filter feeding organisms by metal contaminated particles were investigated. In our hypotheses the adsorbed metals might desorb in the gastrointestinal tract-due to different physico-chemical conditions-and exert toxic effects. Clay and sand particles, algae and organic material (peat) were artificially contaminated with cadmium and zinc. The contaminated materials were resuspended in standard conditions and toxicity was measured for the water flea Daphnia magna (mortality at 48 hours). As a reference, supernatant solutions were used containing the same concentration of dissolved metal as the suspensions. It was also established that the test concentrations of solid material (250 and 500 mg/l uncontaminated particles) did not cause any mortality within 48 hours. Daphnids are filter feeders: they filtrate large amounts of surrounding water, redrawing particles as a food source. Results strongly indicate that contaminated particles threaten the health of these particle-feeding organisms. Compared to the reference severe acute toxic effects were seen and cadmium accumulation was increased when contaminated solid material was present. Results were essentially the same for the different materials used in the experiments, except for sand contaminated with cadmium. This shows that mineral as well as organic materials can contribute to the particle bound toxicity. Different results were obtained when a static set up was used instead of a flow through set up, illustrating that the route of administration is important to make particles available and thus to evaluate their toxicity. Contaminated particles clearly have toxic potency, not only because they are a continuous source of dissolved xenobiotics, but also because the particle bound fraction can become available within the body of particle feeding organisms. This could lead to unexpected high tissue concentrations. More insight is needed to predict the bioavailability of adsorbed pollutants. Results of this study already indicate that suspended solids should be considered as a separate compartment in risk evaluation of chemicals, effluents or natural surface waters.

PMID: 10948281 [PubMed - indexed for MEDLINE]

Photosynthesis tests as an alternative to growth tests for hazard assessment of toxicant.

Petersen S, Kusk KO.

Department of Environmental Science and Engineering, Building 115, Technical University of Denmark, DK-2800 Lyngby, Denmark.

Acute (3- and 6-h) toxic responses toward Cu, linear alkylbenzene sulfonate (LAS), and tributyltin (TBT) of light-saturated and unsaturated photosynthesis were investigated for Rhodomonas salina and Skeletonema costatum obtained from exponentially growing batch cultures and from chemostat cultures limited by either nitrogen or phosphorus. The sensitivity of the photosynthesis tests were compared to standardized growth tests applied to the same species and toxicants. For Cu and S. costatum the photosynthesis test was up to 300 times more sensitive at light saturation than at light limitation. For the remaining photosynthesis tests no dependence on light condition were found. The photosynthesis tests with Cu and S. costatum were up to 10 times as sensitive as the growth test and most sensitive when the algae were obtained from a phosphate-limited chemostate. For the other photosynthesis tests no dependence on the growth condition were found, and the photosynthesis tests were as sensitive as the growth test. Photosynthesis tests offer an alternative to growth tests for hazard assessment of toxicants.

PMID: 10629275 [PubMed - indexed for MEDLINE]

Induced metal tolerance in microbenthic communities from three lowland rivers with different metal loads

Lehmann V V, Tubbing GM, Admiraal W.

University of Amsterdam, ARISE, Department of Ecotoxicology, Kruislaan 320, 1098 SM Amsterdam, The Netherlands.

The response of microbenthic communities to sustained metal stress was studied in three lowland rivers with different levels of pollution. Tolerance against zinc and cadmium was determined in short-term toxicity tests with microbenthic assemblages colonizing glass discs. Photosynthetic activity served as an endpoint in tests for algae, whereas for bacteria thymidine incorporation was determined. For bacterial assemblages from unpolluted locations, EC50 values in short-term tests ranged between 6.7 and 56.2 &mgr;M zinc, and 8.7 and 25.5 &mgr;M cadmium, respectively. Bacterial assemblages from the two most polluted sites were significantly more tolerant for zinc (EC50: 994 &mgr;M and >1,000 &mgr;M) and cadmium (EC50: 218 &mgr;M and 154 &mgr;M). Results indicated a shift in community composition toward pollution-adapted organisms when a threshold concentration of 1 &mgr;M zinc is exceeded. Although an increasing community tolerance was also indicated for algae, EC50 values for microbenthic algae from all sites exceeded in most cases the highest metal concentrations tested (Zn: 1,000 &mgr;M; Cd: 320 &mgr;M). Since species composition of algal assemblages was found to change at much lower metal levels, it is concluded that short-term toxicity tests measuring photosynthesis inhibition do not reflect well the long-term effects of these metals. Toxic effects of metals on both algal and bacterial assemblages are attenuated by precipitation and complexing capacities of the biofilm.

PMID: 10227857 [PubMed - as supplied by publisher]

The use of bioassays and toxicity identification evaluation (TIE) procedures to assess recovery and effectiveness of remedial activities in a mine drainage-impacted stream system.

Deanovic L, Connor VM, Knight AW, Maier KJ.

Department of Anatomy, Physiology, and Cell Biology, School of Veterinarian Medicine, University of California, Davis, California 95616, USA.

Effluents from Walker Mine and its tailings pile have resulted in toxic concentrations of metals in Dolly and Little Grizzly Creeks. Recent remedial structures have greatly reduced metal loading, however the need to assess recovery of the receiving aquatic ecosystem exists so that future remediation priorities can be established. The objective was to contribute to this assessment using Toxicity Identification Evaluation procedures. Water samples were collected at several sites in Dolly and Little Grizzly Creeks. Untreated samples and samples passed through ion exchange columns, which remove cationic metals, were compared in side-by-side bioassays using Pimephales promelas, Ceriodaphnia dubia, and Selenastrum capricornutum. Samples were analyzed for total and dissolved copper, cadmium, zinc, and iron. Copper was the element responsible for toxicity. Toxicity was detected in the mine discharge and immediately downstream from the tailings where dissolved copper concentrations were 250 microg/L and 415 microg/L, respectively. Toxicity decreased at downstream sites but extended at least 6.4 km downstream. Improvement in bioassay performance by the treated waters verified metal toxicity. The results indicate that the mine effluent and tailings pile currently have the heaviest impact on Dolly and Little Grizzly Creeks and should be given the highest priority in future remedial programs.

PMID: 9828258 [PubMed - indexed for MEDLINE]

Detection of toxic organometallic complexes in wastewaters using algal assays.

Wong SL, Nakamoto L, Wainwright JF.

Ontario Ministry of Environment and Energy, Environmental Monitoring and Reporting Branch, Biomonitoring Section, 125 Resources Rd, Etobicoke, Ontario, M9P 3V6, Canada.

Chlorella (a unicellular green alga) and Cladophora (a filamentous alga) were used in algal assays to identify the presence and toxicity of organometallic complexes in four industrial wastewaters. Toxicities of inorganic Pb and organometallic compounds (trimethyl, tetramethyl and tetraethyl leads, cacodylic acid and Cu-picolinate) were examined, using algal cells grown in 10% BBM solution. Inorganic Pb and organometallic compounds altered the fine structure of Chlorella cells in a distinguishable manner. X-ray microanalysis revealed that organometallic compounds accumulated in the neutral lipids of Cladophora cells. By applying the above techniques to the wastewater assays, two of the four wastewaters tested were found to contain organometallic complexes. Wastewater from a chemical company contained only traces of organo-Cu, but one mining effluent contained significant quantities of organo-Cu and organo-Pb, and traces of organo-Cr and organo-Tl (thallium). These studies suggest that X-ray microanalysis of algae may be a useful tool in identifying aquatic systems contaminated with metals and organometallic compounds.

PMID: 9175500 [PubMed - indexed for MEDLINE]

Acute and chronic exposure of Dunaliella salina and Chlamydomonas bullosa to copper and cadmium: effects on growth.

Visviki I, Rachlin JW.

Department of Biological Sciences, Lehman College of CUNY, Bronx 10468.

Effective copper and cadmium concentrations which limited the growth of two chlorophytes by 50%, EC(50)s, after 96 h of static exposure were determined. EC(50)s were 5.94 microM copper and 4.55 microM cadmium for Dunaliella salina, and 0.78 microM copper and 0.025 microM cadmium for Chlamydomonas bullosa. The relationship of the two cations was synergistic towards the growth of both species. Chronic exposure to 4.5 x 10(-6) microM cadmium or 4.9 x 10(-4) microM copper increased the sensitivity of C. bullosa by 26% and 29% towards cadmium and copper, respectively. Changes in co-tolerance were not observed. Cd-treated D. salina was 50% more tolerant towards this cation, whereas Cu-treated cultures showed extreme sensitivity towards copper and "co-sensitivity" towards cadmium. Furthermore, the phylogenetic hypothesis, predictive of toxic response, failed to hold at the familial level.

PMID: 8311507 [PubMed - indexed for MEDLINE]

Acute and chronic exposure of Dunaliella salina and Chlamydomonas bullosa to copper and cadmium: effects of ultrastructure.

Visviki I, Rachlin JW.

Department of Biological Sciences, Lehman College of CUNY, Bronx 10468.

The ultrastructural changes of Dunaliella salina and Chlamydomonas bullosa taking place after short term exposure to established copper and/or cadmium EC(50) or exposure to low levels of these cations for 8 months were examined. Cadmium had a greater impact on the ultrastructure of these species than copper. Metal stress affected a variety of cellular parameters including total cell volume, pyrenoid, nucleus, starch granules, polyphosphate bodies, lipids, vacuoles, cell wall, and periplasmalemmal space. The measurements of these cellular parameters used the technique of electron microscopic stereoscopic morphometry. Differences resulting from acute vs. chronic exposure to the cations are documented.

PMID: 8311508 [PubMed - indexed for MEDLINE]

The growth response of the green alga Chlorella vulgaris to combined divalent cation exposure.

Rachlin JW, Grosso A.

Department of Biological Sciences, Lehman College, City University of New York, West, Bronx 10468-1589.

Using the growth response of the green alga Chlorella vulgaris as a model system, the effects of combinations of the environmentally active cations Cd, Co, and Cu were evaluated. The 96-h static EC50 for these cations to C. vulgaris were, respectively, 0.89 microM, 9.0 microM, and 2.8 microM, yielding a toxicity series such that Cd > Cu > Co. The cation combinations of Cd + Cu, and Cu + Co acted synergistically, while Cd + Co, and the tri-metallic combination Cd + Cu + Co resulted in antagonistic interactions. Examination of these toxic combinations at 24, 48, 72, and 96 h indicate that the cellular response is not a uniform one. Failure of energy dispersive X-ray spectrophotometric analysis to demonstrate any intracellular incorporation of these cations (except for a weak cytoplasmic Cu peak at the 8.0 KEV position) suggests that the toxic actions of these cations at EC50 concentrations are exerted at the level of the plasma membrane.

PMID: 8466290 [PubMed - indexed for MEDLINE]

Ultrastructural changes in Dunaliella minuta following acute and chronic exposure to copper and cadmium.

Visviki I, Rachlin JW.

Department of Biological Sciences, Lehman College of CUNY, Bronx 10468.

The ultrastructural changes taking place after short-term acute exposure to copper, cadmium and a combination of the two metals were examined. Additionally, the effects of long-term (8 months) exposure to ambient concentrations of these metals were investigated. Exposure to 0.34 microM cadmium affected the photosynthetic potential of this alga, by reducing the relative volume of the chloroplast by 23.27%. It also led to 74.6% increase in the relative volume of starch granules. Cells challenged with 0.34 microM cadmium and 7.57 microM copper had 33.49% larger volumes than controls, and their relative lipid volumes increased by 170%. In contrast, the relative volume of their pyrenoids decreased by 41.46%. Similar results were obtained after chronic exposure to 4.9 x 10(-4) microM copper with the relative volume of the pyrenoid being 28% smaller than the controls.

PMID: 1444584 [PubMed - indexed for MEDLINE]

Toxicity of construction materials in the marine environment: a comparison of chromated-copper-arsenate-treated wood and recycled plastic.

Weis P, Weis JS, Greenberg A, Nosker TJ.

Department of Anatomy, University of Medicine and Dentistry of New Jersey, Newark 07103.

Previous studies have demonstrated leaching from chromated-copper-arsenate (CCA)-treated wood, which is used in pilings and bulkheads, and resulting toxicity to various estuarine organisms. The current study compared effects of leachates from CCA-treated wood with those of recycled plastic "lumber," a possible alternative construction material. Limb regeneration in fiddler crabs, while depressed in leachates from CCA wood, was accelerated in three formulations of recycled plastics. The acceleration was reduced in subsequent trials with the same pieces of plastic. Using a sea urchin fertilization test, no effects were seen in 1- and 3-day leachates from the plastics. However, CCA wood reduced fertilization by 90%, and totally inhibited larval development of those that did fertilize. A smaller piece of wood, one-tenth the size (0.4 cm2), did not have a significant effect on fertilization or development. With 1-3 weeks of leaching, significant reductions in fertilization were seen in sea urchin gametes exposed to one plastic formulation and no fertilization was seen in leachates from the small piece of CCA wood. Two formulations enriched to 30% polystyrene (PS) had no significant effect on fertilization, but did reduce larval growth. When the same pieces of plastic and wood were used for a second set of experiments, all three formulations of plastic, as well as the small piece of wood, inhibited fertilization significantly, and one of the 30% PS formulations and the wood caused reduced larval growth. In another assay, snails and an alga were exposed to plastics for two months with no observed effect; the CCA leachates caused 100% snail mortality within one week and chlorosis of the alga.(ABSTRACT TRUNCATED AT 250 WORDS)

PMID: 1554259 [PubMed - indexed for MEDLINE]

Metal pollution and its impact on algae in flowing waters in India.

Sudhakar G, Jyothi B, Venkateswarlu V.

Department of Botany, Osmania University, Hyderabad, India.

Metal pollution in the river Godavari in India, due to discharges of liquid wastes from a paper mill, has been studied for a period of two years. At the discharge point and 1 km from the point of discharge, iron, manganese, and zinc were recorded in high concentrations, whereas cadmium and chromium were observed in low concentrations. No metal was in detectable concentration in water before the river receives the effluents. A considerable drop in pH values and an appreciable increase in organic matter, hardness, and calcium levels were noticed after entry of wastes. Diatoms were more diversified in fresh water, whereas cyanobacteria were more prevalent both qualitatively and quantitatively at the polluted stations. Mathematical equations involving heavy metals and physicochemical factors were drawn for better understanding of the distribution of algae.

PMID: 1759850 [PubMed - indexed for MEDLINE]

The effects of pH on the growth of Chlorella vulgaris and its interactions with cadmium toxicity.

Rachlin JW, Grosso A.

Department of Biological Sciences, Lehman College of the City University of New York, Bronx 10468-1589.

The effects of pH alone, and in combination with exposure to 0.89 microM cadmium, on the growth response of the green alga Chlorella vulgaris were evaluated. Acidic (3.0-6.2) and alkaline (8.3-9.0) pH values retarded the growth of this alga. Optimal growth occurred when the pH of the medium was adjusted to values of 7.5 and 8.0. When the cells were exposed to pH adjusted medium plus the presence of 0.89 microM Cd, a value known to reduce population growth by 50% at the control pH of 6.9, the affects were additive at the acidic (3.0-5.0) pH ranges. At alkaline pH values of 8.3-9.0 all toxicity responses could be explained by pH adjustment alone, indicating that additional cadmium toxicity was absent. At pH values of 7.5 and 8.0, cadmium toxicity was mitigated against, and resultant growth at pH 8.0 was at the same enhanced rate as this pH without cadmium.

PMID: 2069424 [PubMed - indexed for MEDLINE]

The toxic action and interactions of copper and cadmium to the marine alga Dunaliella minuta, in both acute and chronic exposure.

Visviki I, Rachlin JW.

Department of Biological Sciences, Lehman College of C.U.N.Y., Bronx 10468.

The effective concentrations of copper and cadmium which reduced the population growth of Dunaliella minuta by 50% after 96 h of static exposure, were determined to be 7.57 microM Cu and 0.34 microM Cd. Short-term static exposure to both metals indicated that their combined action is antagonistic with respect to growth of this chlorophyte. Additionally, long-term exposure to low levels of Cu or Cd led to the acquisition of tolerance towards Cu and Cd, respectively, and co-tolerance towards Cu.

PMID: 2015003 [PubMed - indexed for MEDLINE]

A morphometric and X-ray energy dispersive approach to monitoring pH-altered cadmium toxicity in Anabaena flos-aquae.

Rai LC, Jensen TE, Rachlin JW.

Department of Biological Sciences, Lehman College, Bronx, New York 10468.

Cadmium toxicity and uptake as influenced by different pH values have been studied in the freshwater cyanobacterium Anabaena flos-aquae, using the techniques of morphometric analysis, x-ray energy dispersive analysis and atomic absorption spectrophotometry. A general reduction in cell dimension, thylakoid surface area, number and volume of polyhedral bodies, polyphosphate bodies, cyanophycin granules, lipid bodies, membrane limited crystalline inclusions, volume and number of wall layers and mesosomes was observed. These reductions were more pronounced in both acidic and alkaline medium than at pH 7.2. At 0.12 microM Cd, the uptake increased with alkaline pH values, and uptake was greater at pH 7.2 than at either acid or alkaline pHs. Lysis of cell wall at 1.18 microM Cd showed the following decreasing trend: pH 4.0 greater than pH 5.5 greater than pH 10.0 greater than pH 9.0 greater than pH 7.2. There was a total loss of lipid bodies at 1.18 microM Cd at all pH values listed. It is suggested that these techniques can be successfully employed for bioassay studies of metal toxicity to algae. In particular, cell wall lysis and loss of lipids by algae are good indicators of pH effects and metal toxicity in the aquatic ecosystem.

PMID: 2117425 [PubMed - indexed for MEDLINE]

Measurement of manganese amelioration of cadmium toxicity in Chlorella pyrenoidosa using turbidostat culture.

Bennett WN.

Department of Biological Sciences, University of Wisconsin-Milwaukee 53201.

Cadmium (Cd) toxicity and amelioration of Cd toxicity by Mn were measured in Chlorella pyrenoidosa, using turbidostat culture. The responses were measured in terms of the maximum specific growth rate, mu max, of the populations. In turbidostat culture mu max is a dependent variable that can be measured continuously. Cd (as CdCl2.2.5 H2O) was added to control populations at a concentration of 1.8 microM Cd. Toxicity was expressed after a 5 generation lag and resulted in a mu max steady state 62% lower than the initial control after 2 generations. With continued Cd exposure, Mn (as MnCl2.6H2O) was then added stepwise to a concentration of 10.4 microM Mn which caused a rapid, immediate increase in mu max followed by linear increase until a steady-state plateau was reached at a mu max 90% of control. The ameliorative response spanned 20 culture generations. After addition of Mn (10.4 microM), cellular Cd concentration did not change and cellular Mn concentration increased. Increase in mean cell size accompanied Cd exposure and was significantly decreased when supplemented with 10.4 microM Mn. Possible mechanisms of the amelioration are discussed.

PMID: 2331145 [PubMed - indexed for MEDLINE]

Comparison of estuarine species sensitivities to three toxicants.

Roberts MH Jr, Warinner JE, Tsai CF, Wright D, Cronin LE.

PMID: 7165388 [PubMed - indexed for MEDLINE]

Toxicity and bioaccumulation of cadmium in the colonial green alga Scenedesmus obliquus.

Cain JR, Paschal DC, Hayden CM.

A laboratory investigation was conducted to study the extent and efficiency of cadmium bioaccumulation in Scenedesmus obliquus by subjecting this alga to varied sublethal Cd concentrations. The influence of cell population age on Cd bioaccumulation was also studied. Under the experimental conditions employed, growth was not significantly affected by Cd concentrations ranging from 0.01 ppm to 1.00 ppm. At concentrations above 1.00 ppm, however, growth was inhibited markedly. Increases in external Cd concentration caused an increase in total bioaccumulation over the entire range of concentrations, which did not significantly affect growth. Efficiency of Cd bioaccumulation was also concentration dependent, but maximum accumulation efficiency occurred in a medium with a Cd concentration lower than that medium in which maximum total bioaccumulation occurred. Age of the cell population influenced the extent of Cd bioaccumulation. Rapidly growing, young cultures accumulated less Cd than older cultures approaching stationary growth phase.

PMID: 7369788 [PubMed - indexed for MEDLINE]

Toxicity of zinc, copper and lead to Chlorophyta from flowing waters.

Whitton BA.

PMID: 5474133 [PubMed - indexed for MEDLINE]

Palm island reconsidered. Was it copper poisoning?

Prociv P.

Department of Parasitology, University of Queensland, St Lucia.

The clinical features of the 'Palm Island mystery disease' cannot be explained on the basis of toxocariasis, nor do they correlate with the known manifestations of algal toxicity. A detailed review of acute and chronic copper poisoning in humans and laboratory animals supports this as a possible explanation for the epidemic. The mechanisms involved in copper intoxication are discussed briefly, and a scenario is proposed to explain the occurrence and pathogenesis of the outbreak.

Publication Types:

Review

Review, Tutorial

PMID: 3314834 [PubMed - indexed for MEDLINE]

Cadmium resistance of achlorophyllous Euglena gracilis cells: constitutive overexpression of two heat-shock proteins.

Barque JP, Chacun H, Marouby S, Bonaly J.

Laboratoire Metabolisme Cellulaire et Xenobiotiques, Faculte de Pharmacie, Chatenay-Malabry, France.

The heat-shock response of Euglena gracilis was studied by cell labeling at both the normal growth temperature (23 degrees C) and an elevated temperature (35 degrees C). Analysis of the labeled proteins by two-dimensional polyacrylamide gel electrophoresis indicated that the rate of synthesis of two polypeptides p55 (55 kDa) and p40 (40 kDa) increased in cells labeled at the highest temperature studied. These polypeptides are also overexpressed in Cadmium-resistant Euglena gracilis cells labeled at the normal growth temperature (23 degrees C). On the basis of these results, p55 and p40 appear to be heat-shock proteins involved in some steps of the acquired Cd-resistance process in Euglena gracilis cells.

PMID: 8074701 [PubMed - indexed for MEDLINE]

Insertion mutagenesis of Chlamydomonas reinhardtii by electroporation and heterologous DNA.

Tang DK, Qiao SY, Wu M.

Dept. of Biology, Hong Kong University of Science and Technology, Kowloon.

We introduced plasmid pCmVCAT containing a chloramphenicol acetyltransferase (CAT) gene, flanked by the cauliflower mosaic virus 35S promoter and nopaline synthase polyadenylation sequences, into Chlamydomonas reinhardtii by electroporation; chloramphenicol (CAM) resistance was used for selection. Several mutants with aberrant response to cadmium (Cd) toxicity were obtained by screening CAM resistant transformants. Southern blot analysis showed random integration of pCmVCAT sequence into the nuclear genome. Expression of CAT gene was confirmed by the detection of CAT gene transcript in Northern blot analysis and the detection of CAT enzyme by ELISA assay. This study demonstrated the feasibility of transforming Chlamydomonas reinhardtii with heterologous DNA by electroporation, and the expression of heterologous gene, in this alga.

PMID: 7580998 [PubMed - indexed for MEDLINE]

Genetic mechanisms involved in the adaptation of marine algae to heavy metal pollution.

Morris CA, Nicolaus B, Kille P, Harwood JL.

School of Molecular and Medical Biosciences, University of Wales, Cardiff.

PMID: 9649828 [PubMed - indexed for MEDLINE]

Effect of heavy metals on lipids from the freshwater alga Selenastrum capricornutum.

Riches CJ, Robinson PK, Rolph CE.

Department of Applied Biology, University of Central Lancashire, Preston, UK.

PMID: 8736832 [PubMed - indexed for MEDLINE]

DNA distribution in the cell cycle of Euglena gracilis. Cytofluorometry of zinc deficient cells.

Falchuk KH, Drishan A, Vallee BL.

Analysis of DNA content of intact cells by laser induced cytofluorometry permits dynamic studies of the cell cycle in the synchronously dividing eukaryote Euglena gracilis. In this manner, the effects of zinc deficiency and cadmium toxicity on in situ DNA synthesis and cell division of this organism have been studied. In the G-1 hase of the cell cycle, prior to initiation of DNA synthesis, the DNA content of synchronously growing E. gracilis is characteristic of cells with an ureplicated genome. In S phase there is a progressive increase in DNA content which leads to genome duplication as the cells enter G2. In the subsequent mitosis all cells divide. Cytofluorometric definition of DNA content serves as a standard of reference to study variables which alter or block each stage of the cell cycle. Growth in zinc dificient media inhibits cell division. The DNA content of such zinc dificnet cells is characteristic of a population of cells blocked in S/G2 with a small fraction in G1. Moreover, cells synchronized in G1 and placed in zinc deficient media do not progress into S phase. Cadmium also inhibits cell division, and the DNA content of these blocked cells is three to four times greater than that of cells in G1. Zinc is essential for the biochemical events of the premitotic state which include initiation of DNA synthesis, DNA synthesis, and progression from G-2 to mitosis. Cadminum-induced derangements of the cell cycle include alterations in regulation cellular DNA content.

PMID: 807244 [PubMed - indexed for MEDLINE]

Three dose-dependent stages of the effect of copper ions on functional activity of biological systems.

Bozhkov AI.

Biological Research Institute, Kharkov State University, Ukraine. [email protected]

The dose-dependent effects of copper sulfate on the proliferation and functional activity of the genome of liver cells and of algae in vivo and the activity of RNA-polymerase and glucose-6-phosphatase and formation of malonic dialdehyde in vitro were investigated. Administration of various doses of copper sulfate causes a dose-dependent three-phase response of biological systems comprising a stimulation phase, a latent phase, and a phase of inhibition. The degree of manifestation of the three-phase response depends on the functional activity of the biological system. The consecutive dose-dependent binding of metal ions with components of cells forms the basis of the three-phase response to copper ions.

PMID: 9159868 [PubMed - indexed for MEDLINE]

Impact of bimetallic combinations of Cu, Ni and Fe on growth rate, uptake of nitrate and ammonium, 14CO2 fixation, nitrate reductase and urease activity of Chlorella vulgaris.

Mallick N, Singh AK, Rai LC.

Laboratory of Algal Biology, Banaras Hindu University, Varanas, India.

The toxicity of Cu, Ni and Fe individually, as well as in combination (Cu + Ni, Cu + Fe, Ni + Fe), on growth-rate depression, uptake of NO3- and NH4+, photosynthesis, nitrate reductase and urease activity of Chlorella vulgaris has been studied. All the test metals when used individually showed pronounced toxicity on all the parameters studied. However, their interactive effect was mostly antagonistic except for Cu + Ni (synergism). Pre-addition of Fe offered more protection to the cells against copper and nickel toxicity. The data of statistical analysis reconfirmed that 14CO2 uptake is the most sensitive parameter (significant at P less than 0.005, both for time and treatment) than others in metal toxicity assessment. However, these results suggest further that exposure time and sequence of metal addition are very important in biomonitoring of heavy metal toxicity.

PMID: 2167714 [PubMed - indexed for MEDLINE]

Removal of heavy metals by two free floating aquatic macrophytes.

Mallick N, Shardendu, Rai LC.

Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, India.

A concentration-dependent decrease in biomass, protein, RNA, DNA, and nutrient (NO3(-) and PO4(3-)) uptake of Lemna minor and Azolla pinnata by Cr, Ni, and Zn was detected. Cr was found to exert maximum toxicity followed by Ni and Zn. Metal uptake was dependent on time and concentration of metal in the external medium. Both the macrophytes, however, showed preference for Zn followed by Ni and Cr. The uptake kinetics also revealed a low Vmax and high Km for Cr. L. minor was more efficient in accumulating Zn and Cr than A. pinnata in Ni. Compared to immobilized algae and bacterial capsules the test macrophytes showed a greater efficiency for metal removal.

PMID: 8988809 [PubMed - indexed for MEDLINE]

Effect of Cu and Ni on growth, mineral uptake, photosynthesis and enzyme activities of Chlorella vulgaris at different pH values.

Rai PK, Mallick N, Rai LC.

Laboratory of Algal Biology, Banaras Hindu University, Varanasi, India.

A pH dependent reduction in growth, pigment, ATP content, O2- evolution, carbon fixation, photosynthetic electron transport system, nutrient uptake (NO3- and NH4+), nitrate reductase, and ATPase activities and increase in K+ efflux of Chlorella vulgaris was noticed following supplementation of Cu and Ni to the culture medium. PS II was found to be more sensitive to both pH and metals than PS I. Though, nitrate reductase (NR) was more sensitive to both pH and metals, the ATPase was however, more sensitive to metals but less sensitive to acidic pH. Acid pH was found to inhibit the nutrient (NO3- and NH4+) uptake and nitrate reductase in a non-competitive manner. The inhibition produced by the test metals alone was of non-competitive type for NO3- uptake, nitrate reductase and ATPase and competitive for NH4+ uptake. Acidity not only inhibited the metabolic variables directly but also through facilitated uptake of metals and increased membrane permeability. A very low sensitivity of ATPase to acidic pH seems to be responsible for the survival of algae in acid environment.

PMID: 8024720 [PubMed - indexed for MEDLINE]

Metal induced inhibition of photosynthesis, photosynthetic electron transport chain and ATP content of Anabaena doliolum and Chlorella vulgaris: interaction with exogenous ATP.

Mallick N, Rai LC.

Laboratory of Algal Biology, Banaras Hindu University, Varanasi, India.

This study demonstrates a concentration dependent inhibition of carbon fixation, O2 evolution, photosynthetic electron transport chain and ATP content of A. doliolum and C. vulgaris by Cu, Ni and Fe. Although the mode of inhibition of photosynthetic electron transport chain of both the algae was similar, PS II depicted greater sensitivity to the test metals used. The toxicity in both organisms was Cu > Ni > Fe. A. doliolum was, however, more sensitive to Cu and Ni, and C. vulgaris to Fe. Toxicity was generally dependent on metal uptake, which in turn was dependent on their concentrations in the external medium. A partial restoration of nutrient uptake, carbon fixation, and enzyme activities following supplementation of exogenous ATP suggests that ATP regulates toxicity through chelation.

PMID: 1449660 [PubMed - indexed for MEDLINE]

Removal of Cu and Ni by free and immobilized microalgae.

Wong MH, Pak DC.

Department of Biology, Hong Kong Baptist College, Kowloon.

The present investigation evaluated the effectiveness of Chlorella cells in concentrating Cu and Ni in their cells and thereby removing the two metals from solution. The removal efficiency of the two metals by free and immobilized algal cells were further studied. (1) Four types of Chlorella cells, namely Chlorella pyrenoidosa (26) (from Carolina Biological Supplies Company), Chlorella HKBC-1 and-2 (isolated from a polluted stream receiving wastewater from several electroplating factories) and Chlorella HKBC-3 (from a clean water pond) were subjected to different concentrations of Cu and Ni accordingly. It was revealed that Chlorella HKBC-1 was the most tolerant species to Cu and Ni as reflected by their highest values of 48 h and 96 h "Highest no effect concentrations" (The highest concentration of the tested substance that does not inhibit the growth rate of the alga: Cu 2 and Ni 10 mg/l at 48 h, Cu 2 and Ni 5 at 96 h). This was followed by C. pyrenoidosa (26) and then C. HKBC-2 while C. HKBC-3 had the lowest tolerance to the two metals (Cu 0.5 and Ni 2 at 48 h; Cu 0.5 and Ni 1 mg/l at 96 h). (2) It was further revealed that C. HKBC-1 had higher concentration factors and removal efficiencies of Ni (734-963 mg/l, 16.3-18.7%) and C. HKBC-2 had higher concentration factors and removal efficiencies of Cu (2316-2839 mg/l, 53.7-66%) when exposed to lower concentrations of Cu (0.5, 1 and 2 mg/l) and Ni (5, 10 and 13 mg/l). (3) By treating the free and immobilized algal cells (algal cells entrapped in alginate beads) with different concentrations of Cu and Ni, it was observed that free cells had higher concentration factors and removal efficiencies when compared with immobilized cells (free cells: Cu 1577-3056 mg/l, 24.2-71.4%; Ni 355-849 mg/l, 4.8-18.7%; immobilized cells: Cu 453-935 mg/l, 13.9-53.2%; Ni 244-486 mg/l, 3.2-11.9%).

PMID: 1642794 [PubMed - indexed for MEDLINE]

Impact of spectral quality on toxicity of iron in Anabaena doliolum and Chlorella vulgaris.

Mallick N, Rai LC.

Laboratory of Algal Biology, Banaras Hindu University, Varanasi, India.

Evidence is presented on the effects of low and high concentrations of iron on growth, nutrient uptake (NH+4 and NO3-), photosynthesis (CO2-fixation and O2-evolution) and nitrate reductase (NR) activity of A. doliolum and C. vulgaris under monochromatic irradiation. Control cultures (not treated with FeCl3) showed maximum growth under fluorescent followed by red, yellow, blue and green lights (fluorescent greater than yellow greater than red greater than blue greater than green). The inhibition was of synergistic type under yellow and red lights at all the iron concentrations tested. However, under blue and green lights the interaction was less than additive type. All the processes studied responded in a similar manner to a particular color of light. Under fluorescent light at low Fe concentrations, stimulation of NR, 14CO2-fixation and O2-evolution was noticed in both the test organisms. However, even the lowest concentration of iron tested was inhibitory to these processes under yellow and red lights. Under blue light at 20 micrograms.ml-1 Fe, NR activity was inhibited by 98%. This study clearly demonstrates that metal toxicity to phytoplankton will be greatly affected by spectral quality, hence it will have great significance in limnological research.

PMID: 1586469 [PubMed - indexed for MEDLINE]

Microalgae as bioabsorbents for treating mixture of electroplating and sewage effluent.

Chan SS, Chow H, Wong MH.

Department of Biology, Hong Kong Baptist College, Kowloon.

The effectiveness of copper and nickel uptake by microalgae grown in the mixture of electroplating effluent and sewage was studied. The results showed that a high percentage of copper removal (68.1%-88.2%) was achieved by Chlorella pyrenoidosa (strain No. 26) reared in the mixture of 90% electroplating effluent and 10% raw sewage during the first 3 days despite the fact that cell growth was inhibited. Similar results were also obtained by using Chlorella HKBC-C3, another species collected from one of the heavy metal polluted sites in Hong Kong, isolated and cultured in the Biology Department. There was no significant difference (P greater than 0.05) in the removal of copper and nickel from the effluent between these 2 algal species. However, it was noted that removal of nickel from the mixture by the two species were comparatively lower (less than 20%) than the removal of copper (greater than 68%).

PMID: 1764214 [PubMed - indexed for MEDLINE]

Identification of a copper-sensitive ascorbate peroxidase in the unicellular green alga Selenastrum capricornutum.

Sauser KR, Liu JK, Wong TY.

Department of Microbiology and Molecular Cell Sciences, University of Memphis, TN 38152-6041, USA.

Extracts from the unicellular green alga Selenastrum capricornutum exhibit high superoxide dismutase activity, but only traces of catalase activity. The excess hydrogen peroxide (H2O2) generated by the superoxide dismutase in S. capricornutum may be degraded by a unique peroxidase. This peroxidase has a high specificity for ascorbate as its electron donor. The enzyme has an optimum pH at 8, is insensitive to cyanide and is inhibited by oxine. Addition of low concentrations of copper to algal cultures stimulates the peroxidase activity threefold. This enzymatic system could be used as a sensitive bioindicator for copper in fresh water.

PMID: 9243795 [PubMed - indexed for MEDLINE]

Impact of aluminium, fluoride and fluoroaluminate complex on ATPase activity of Nostoc linckia and Chlorella vulgaris.

Husaini Y, Rai LC, Mallick N.

Department of Botany, Banaras Hindu University, Varanasi, India.

This study demonstrates a pH-dependent inhibition of Mg(2+)- and Ca(2+)-ATPase activities of Nostoc linckia and Chlorella vulgaris exposed to AlCl3, AlF3, NaF and AlCl3+NaF together. AlF3 and the combination of AlCl3+NaF were more inhibitory to both the enzymes as compared with AlCl3 and NaF. Toxicity of the test compounds increased with increasing acidity. Interaction of AlCl3+NaF was additive on N. linckia and C. vulgaris, respectively, at pH 7.5 and 6.8, and synergistic at pH 6.0 and 4.5. In the presence of 60 and 100 microM PO4(3-) an increased NaF concentration (in the AlCl3+NaF combination) was required to produce the same degree of inhibition in ATP synthesis and ATPase activity. Toxicity of fluoroaluminate was reduced in the presence of EDTA and citrate. Except for beryllium to some extent, combinations of cadmium, cobalt, iron, manganese, tin and zinc with fluoride were not as effective as aluminium in inhibiting the ATPase activity. The presence of a 100 kDa protein band in SDS-PAGE of both control as well as AlCl3+NaF-treated samples suggested that AlF4- inhibits the ATPase activity by acting as a functional barrier without affecting the structure of the enzyme.

PMID: 8696079 [PubMed - indexed for MEDLINE]

Effect of nickel on certain physiological and biochemical behaviors of an acid tolerant Chlorella vulgaris.

Rai PK, Mallick N, Rai LC.

Laboratory of Algal Biology, Banaras Hindu University, Varanasi, India.

This study concerns the inhibitory effects of acid pH and nickel on growth, nutrient (NO3- and NH4+) uptake, carbon fixation, O2 evolution, electron transport chain and enzyme (nitrate reductase and ATPase) activities of acid tolerant and wild-type strains of Chlorella vulgaris. Though a general reduction in all these variables was noticed with decreasing pH, the tolerant strain was found to be metabolically more active than the wild-type. A reduced cation (NH4+, Na+, K+ and Ca2+) uptake, coupled with a facilitated influx of anions (NH4+, PO4(3-) and HCO3-), suggested the development of a positive membrane potential in acid tolerant Chlorella. Nevertheless, a tremendous increase in ATPase activity at decreasing pH revealed the involvement of superactive ATPase in exporting H+ ions and keeping the internal pH neutral. A difference in Na+ and K+ efflux of the two strains at decreasing pH suggests there is a difference in membrane permeability. The low toxicity of Ni in the acid tolerant strain may be due to the low Ni uptake brought about by a change in membrane potential as well as in permeability. Hence, the development of superactive ATPase and a change in both membrane potential and permeability not only offers protection against acidity, but also co-tolerance to metals.

PMID: 8148621 [PubMed - indexed for MEDLINE]

Effects of cadmium on Euglena gracilis membrane lipids.

Einicker-Lamas M, Soares MJ, Soares MS, Oliveira MM.

Instituto de Biofisica Carlos Chagas Filho, Centro de Ciencias da Saude, Universidade Federal do Rio de Janeiro, Brasil.

The toxic effects of cadmium (2 micrograms/ml) on membrane lipids and growth of Euglena gracilis were studied using autotrophic (AUTO), heterotrophic (DARK) and mixotrophic (LIGHT) cells. Cadmium caused inhibition of cellular proliferation (IC50 1.2 micrograms/ml) and morphological alterations which were most pronounced in chloroplasts. The chlorophyll content of LIGHT cadmium-treated cells was reduced 42.5%. Cadmium also caused an increase in protein and total lipid content per cell in all three cell types. Among the membrane lipids, cholesterol content was lower in cadmium-treated cells cultivated under illumination (AUTO: 0.40 +/- 0.02 vs 0.64 +/- 0.08 and LIGHT: 0.40 +/- 0.09 vs 0.53 +/- 0.01 microgram/10(5) cells). There were no changes in total phospholipid content, although cardiolipin content was altered in all three cell types, and in mixotrophic cells there was an increase in phosphatidylglycerol, a phospholipid typically found in chloroplasts. These results suggest that cadmium has an overall toxic effect on Euglena gracilis and that part of the effect can be ascribed to defects in the structure of chloroplasts and mitochondrial membranes.

PMID: 9181074 [PubMed - indexed for MEDLINE]

Comparative toxicity of thallium(I), thallium(III), and cadmium(II) to the unicellular alga Chlorella isolated from Lake Erie.

Ralph L, Twiss MR.

Department of Chemistry, Biology, and Chemical Engineering, Ryerson Polytechnic University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada.

PMID: 11815797 [PubMed - indexed for MEDLINE]

Interactive effect of manganese, molybdenum, nickel, copper I and II, and vanadium on the freshwater alga Scenedesmus quadricauda.

Fargasova A.

Department of Environmental Science, Faculty of Chemical Technology, Slovak University of Technology, Bratislava, Slovak Republic.

PMID: 11911638 [PubMed - indexed for MEDLINE]

Ecological evaluation of gadolinium toxicity compared with other heavy metals using an aquatic microcosm.

Fuma S, Takeda H, Miyamoto K, Yanagisawa K, Inoue Y, Ishii N, Sugai K, Ishii C, Kawabata Z.

Environmental and Toxicological Sciences Research Group, National Institute of Radiological Sciences, 9-1 Anagawa-4-chome, Inage-ku, Chiba-shi 263-8555 Japan.

PMID: 11116319 [PubMed - indexed for MEDLINE]

Comparison of the sensitivity of Brachionus calyciflorus and Brachionus patulus (Rotifera) to selected heavy metals under low and high food (Chlorella vulgaris) levels.

Sarma SS, Ramirez Perez T, Nandini S.

Biology Career, National Autonomous University of Mexico, Los Reyes, Tlalnepantla, State of Mexico.

PMID: 10857459 [PubMed - indexed for MEDLINE]

Estimation of the hazard concentration of industrial wastewaters using algal bioassay.

Gamila HA, Naglaa FA.

Water Pollution Research Department, National Research Center, Dokki, Cairo, Egypt.

PMID: 10475921 [PubMed - indexed for MEDLINE]

Growth differences in cultured populations of Brachionus plicatilis Muller caused by heavy metal stress as function of microalgal diet.

Moreno-Garrido I, Lubian LM, Soares AM.

ICMAN (Marine Sciences Institute of Andalucia, CSIC), Campus Rio San Pedro, Apdo. Oficial, 11510, Puerto Real, Cadiz, Spain.

PMID: 10475919 [PubMed - indexed for MEDLINE]

Oxygen production rate as a test for determining toxicity of copper to Rhodomonas salina Hill and Wehterbee (Cryptophyceae).

Moreno Garrido I, Lubian LM, Soares AM.

Instituto do Ambiente e Vida (Dpto. Zoologia), Largo Marques de Pombal, s/n, Universidade de Coimbra, 3000 Coimbra, Portugal.

PMID: 10354004 [PubMed - indexed for MEDLINE]

Physiological and biochemical response of Scenedsmus obliquus to combined effects of Al, Ca, and low pH.

Kong FX, Sang WL, Hu W, Li JJ.

State Key Laboratory of Pollution Control and Resources Reuse, Department of Environmental Science and Engineering, Nanjing University, Nanjing, 210093, People's Republic of China.

PMID: 9933315 [PubMed - indexed for MEDLINE]

Heavy metal removal by microalgae.

Travieso L, Canizares RO, Borja R, Benitez F, Dominguez AR, Dupeyron R, Valiente V.

Department of Environmental Pollution Studies (DECA), National Center for Scientific Research (CNIC), Post Office Box 6990, La Habana, Cuba.

PMID: 9933311 [PubMed - indexed for MEDLINE]

Copper-induced oxidative stress in Scenedesmus bijugatus: protective role of free radical scavengers.

Nagalakshmi N, Prasad MN.

Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, India.

PMID: 9841722 [PubMed - indexed for MEDLINE]

Erratum in:

Bull Environ Contam Toxicol 1998 Apr;60(4):667. Stralka K[corrected to Strzalka K]

Toxicity of cadmium and copper in Chlamydomonas reinhardtii wild-type (WT 2137) and cell wall deficient mutant strain (CW 15)

Prasad MN, Drej K, Skawinska A, Strzalka K, Stralka K.

Department of Plant Sciences, University of Hyderabad, India.

PMID: 9470994 [PubMed - indexed for MEDLINE]

Inhibitory effects of mercury and cadmium on seed germination of Enhalus acoroides (L.f.) Royle.

Bonifacio RS, Montano MN.

Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City, Philippines.

PMID: 9484555 [PubMed - indexed for MEDLINE]

Effect of mercury on the growth of Chlamydomonas reinhardtii.

Weiss-Magasic C, Lustigman B, Lee LH.

Montclair State University, Upper Montclair, New Jersey 07043, USA.

PMID: 9323236 [PubMed - indexed for MEDLINE]

Excretion of lead as a mechanism for survival in Chrissia halyi (Ferguson, 1969).

Prasuna G, Zeba M, Khan MA.

Department of Zoology, Osmania University, Hyderabad, India.

PMID: 8791564 [PubMed - indexed for MEDLINE]

Copper transfer and influence on a marine food chain.

Edding M, Tala F.

Departamento de Biologia Marina, Facultad de Ciencias del Mar, Universidad Catolica del Norte, Casilla 117, Coquimbo, Chile.

PMID: 8694881 [PubMed - indexed for MEDLINE]

New algal enzyme bioassay for the rapid assessment of aquatic toxicity.

Peterson SM, Stauber JL.

CSIRO Division of Coal and Energy Technology, Center for Advanced Analytical Chemistry, Menai, NSW, Australia.

PMID: 8661858 [PubMed - indexed for MEDLINE]

Effects of metals on alpha-amylase activity in the digestive gland of the green mussel, Perna viridis L.

Yan T, Teo LH, Sin YM.

Department of Zoology, National University of Singapore, Singapore.

PMID: 8645929 [PubMed - indexed for MEDLINE]

Detection and toxicity of titanium from pulp and paper effluents.

Wong SL, Nakamoto L, Wainwright JF.

Ontario Ministry of Environment and Energy, Environmental Monitoring and Reporting Branch, Etobicoke, Canada.

PMID: 8601068 [PubMed - indexed for MEDLINE]

Effect of aluminum and zinc on enzyme activities in the green alga Selenastrum capricornutum.

Kong FX, Chen Y.

Department of Environmental Science and Engineering, Nanjing University, People's Republic of China.

PMID: 8563211 [PubMed - indexed for MEDLINE]

Effects of cobalt and pH on the growth of Chlamydomonas reinhardtii.

Lustigman B, Lee LH, Weiss-Magasic C.

Biology Department, Montclair State College, New Jersey 07043, USA.

PMID: 7663092 [PubMed - indexed for MEDLINE]

Effects of nickel and pH on the growth of Chlorella vulgaris.

Lustigman B, Lee LH, Khalil A.

Biology Department, Montclair State College, New Jersey 07043, USA.

PMID: 7663093 [PubMed - indexed for MEDLINE]

Response of the marine microalga Dunaliella tertiolecta (Chlorophyceae) to copper toxicity in short time experiments.

Abalde J, Cid A, Reiriz S, Torres E, Herrero C.

Departamento de Biologia Celular y Molecular, Facultad de Ciencias, Universidad de La Coruna, Spain.

PMID: 7742642 [PubMed - indexed for MEDLINE]

Comparative toxicity of five metals on various biological subjects.

Fargasova A.

Slovak Technical University, Faculty of Chemical Technology, Department of Environmental Sciences, Bratislava.

PMID: 8086718 [PubMed - indexed for MEDLINE]

Epilithic extracellular-enzyme activity in a zinc-contaminated stream.

Chappell KR, Goulder R.

Department of Applied Biology, University of Hull, United Kingdom.

PMID: 8123993 [PubMed - indexed for MEDLINE]

Cell-surface changes in cadmium-resistant Euglena: studies using lectin-binding techniques and flow cytometry.

Bonaly J, Brochiero E.

Laboratorie Metabolisme Cellulaire et Xenobiotiques, Faculte de Pharmacie, Chatenay-Malabry, France.

PMID: 8130417 [PubMed - indexed for MEDLINE]

Effect of glucose, glutamate, and 2-oxoglutarate on mercury toxicity to Chlorella vulgaris.

Mohanty RC, Mohanty L, Mohapatra PK.

Department of Botany, Utkal University, Bhubaneswar, India.

PMID: 8100461 [PubMed - indexed for MEDLINE]

Accumulation and transfer of copper by Oocystis pusilla.

Chang C, Sibley TH.

School of Fisheries, University of Washington, Seattle 98195.

PMID: 8490274 [PubMed - indexed for MEDLINE]

Cadmium induced potassium efflux from Scenedesmus quadricauda.

Reddy GN, Prasad MN.

School of Life Sciences, University of Hyderabad, India.

PMID: 1421855 [PubMed - indexed for MEDLINE]

High cadmium residues observed during a pilot study in shorebirds and their prey downstream from the El Salvador Copper Mine, Chile.

Vermeer K, Castilla JC.

Canadian Wildlife Service, c/o Institute of Ocean Sciences, Sidney, B.C.

PMID: 2018870 [PubMed - indexed for MEDLINE]

Toxicity of nickel and nickel electroplating water to Chlorella pyrenoidosa.

Wong PK, Wong CK.

Department of Biology, Chinese University of Hong Kong, Shatin, N.T.

PMID: 2265275 [PubMed - indexed for MEDLINE]

Life table evaluation of the effects of cadmium exposure on the freshwater cladoceran, Moina macrocopa.

Wong CK, Wong PK.

Department of Biology, Chinese University of Hong Kong, Shatin, N.T.

PMID: 2306530 [PubMed - indexed for MEDLINE]

Reduction of cadmium toxicity to green microalga Stichococcus bacillaris by manganese.

Skowronski T, Pawlik B, Jakubowski M.

Polish Academy of Sciences, Institute of Environmental Engineering, Lublin.

PMID: 3233389 [PubMed - indexed for MEDLINE]

Changes in food [Chlorella] levels and the acute toxicity of cadmium to Daphnia carinata (Daphnidae) and Echinisca triserialis (Macrothricidae) [Crustacea: Cladocera].

Chandini T.

Department of Zoology, University of Delhi, India.

PMID: 3219434 [PubMed - indexed for MEDLINE]

Toxicity of vanadium to different freshwater organisms.

Beusen JM, Neven B.

Studiecentrum voor Ecologie en Bosbouw (LISEC), Genk, Belgium.

PMID: 3663972 [PubMed - indexed for MEDLINE]

Influence of light on chlorophyll, a content of blue-green algae treated with heavy metals.

Azeez PA, Banerjee DK.

PMID: 3107639 [PubMed - indexed for MEDLINE]

Hexavalent chromium effects on carbon assimilation in Selenastrum capricornutum.

Pillard DA, Rocchio PM, Cassidy KM, Stewart SM, Vance BD.

PMID: 3567413 [PubMed - indexed for MEDLINE]

Effect of increasing copper and salinity on glycerol production by Dunaliella salina.

Lustigman B, McCormick JM, Dale G, McLaughlin JJ.

PMID: 3801710 [PubMed - indexed for MEDLINE]

Enhancement of pigment concentrations in Dunaliella tertiolecta as a result of copper toxicity.

Lustigman BK.

PMID: 3779155 [PubMed - indexed for MEDLINE]

Toxicity and accumulation of copper and cadmium in the alga Scenedesmus obliquus LH.

Drbal K, Veber K, Zahradnik J.

PMID: 4016298 [PubMed - indexed for MEDLINE]

Heavy metal tolerance in a cadmium-resistant population of Euglena gracilis.

Bariaud A, Mestre JC.

PMID: 6428489 [PubMed - indexed for MEDLINE]

Comparative study of the trophic transfer of two mercury compounds-HgCl2 and CH3HgCl-between Chlorella vulgaris an Daphnia magna. Influence of temperature.

Boudou A, Ribeyre F.

PMID: 6459811 [PubMed - indexed for MEDLINE]

Morphological changes in the diatom, Tabellaria flocculosa, induced by very low concentrations of cadmium.

Adshead-Simonsen PC, Murray GE, Kushner DJ.

PMID: 7260446 [PubMed - indexed for MEDLINE]

Use of a cell wall-less mutant strain to assess the role of the cell wall in cadmium and mercury tolerance by Chlamydomonas reinhardtii.

Cain JR, Allen RK.

PMID: 7470656 [PubMed - indexed for MEDLINE]

Cadmium toxicity to freshwater algae.

Wong PT, Burnison G, Chau YK.

PMID: 497454 [PubMed - indexed for MEDLINE]

Bioaccumulation and bioamplification of mercury compounds in a second level consumer, Gambusia affinis--temperature effects.

Boudou A, Delarche A, Ribeyre F, Marty R.

PMID: 486786 [PubMed - indexed for MEDLINE]

Thallium: occurrence in the environment and toxicity to fish.

Zitko V, Carson WV, Carson WG.

PMID: 1131433 [PubMed - indexed for MEDLINE]

Molybdenum toxicity: abnormal cellular division of teratogenic appearance in Euglena gracilis.

Colmano G.

PMID: 4205304 [PubMed - indexed for MEDLINE]

[Toxic effect of four heavy metals on the growth of unicellular marine algae]

[Article in French]

Berland BR, Bonin DJ, Kapkov VI, Maestrini SY, Arlhac DP.

The growth inhibition of phytoplankton, resulting from Cd, Cu, Hg and Pb in sea water, has been studied on 18 monospecific strains belonging to different taxonomic groups. Data obtained pointed out that all species are very susceptible to Hg, and slightly to Pb. Effects of Cu and Cd vary with species, but Cu appears to be more toxic with dinoflagellates than with diatoms. In the authors' opinion, these results, obtained under laboratory conditions, cannot immediately be extended to the natural environment.

PMID: 817823 [PubMed - indexed for MEDLINE]

[Toxicity of phenylmercury hydroxide on the fresh water algae Scenedesmus subspicatus W. and W. and Euglena gracilis Klebs]

[Article in French]

Vaidehi BK, Delcourt A, Mestre JC.

PMID: 4218534 [PubMed - indexed for MEDLINE]

[Study model of the mid-range ecotoxicity of chemical substances]

[Article in French]

Jouany JM, Vasseur P, Ferard JF, Lelandais D, Truhaut R.

Semi-chronic ecotoxic effects are measured by studying mortality and reproduction of daphnids, grown in toxic medium and fed with toxic chlorellae during 4 weeks. Toxic biosorption is controlled analytically. Toxicity of Cd++ at a concentration of an order of magnitude of by liter is revealed after 14 days. Cr6+ appears non toxic at concentrations under 25 micrograms/l.

PMID: 3937572 [PubMed - indexed for MEDLINE]

[The effect of 3 mercury derivatives on the growth of Euglena gracilis Z]

[Article in French]

Simeray J, Delcourt A, Mestre JC.

The study of the toxicity of three mercuric derivatives on the growth of Euglena gracilis Z. shows that these chemicals act according to two different ways: quick inhibition of the growth for a peculiar concentration or progressive inhibition characterized by a lag-phase, the significance of which is discussed.

PMID: 145300 [PubMed - indexed for MEDLINE]

Cadmium transport, resistance, and toxicity in bacteria, algae, and fungi.

Trevors JT, Stratton GW, Gadd GM.

Cadmium is an important environmental pollutant and a potent toxicant to bacteria, algae, and fungi. Mechanisms of Cd toxicity and resistance are variable, depending on the organism. It is very clear that the form of the metal and the environment it is studied in, play an important role in how Cd exerts its effect and how the organism(s) responds. A wide range of Cd concentrations have been used to designate resistance in organisms. To date, no concentration has been specified that is applicable to all species studied under standardized conditions. Cadmium exerts its toxic effect(s) over a wide range of concentrations. In most cases, algae and cyanobacteria are the most sensitive organisms, whereas bacteria and fungi appear to be more resistant. In some bacteria, plasmid-encoded resistance can lead to reduced Cd2+ uptake. However, some Gram-negative bacteria without plasmids are just as resistant to Cd as are bacteria containing plasmids encoding for Cd resistance. According to Silver and Misra (1984), there is no evidence for enzymatic or chemical transformations associated with Cd resistance. Insufficient information is available on the genetics of Cd uptake and resistance in cyanobacteria and algae. Mechanisms remain largely unknown at this point in time. Cadmium is toxic to these organisms, causing severe inhibition of such physiological processes as growth, photosynthesis, and nitrogen fixation at concentrations less than 2 ppm, and often in the ppb range (Tables 2 and 3). Cadmium also causes pronounced morphological aberrations in these organisms, which are probably related to deleterious effects on cell division. This may be direct or indirect, as a result of Cd effects on protein synthesis and cellular organelles such as mitochondria and chloroplasts. Cadmium is accumulated internally in algae (Table 4) as a result of a two-phase uptake process. The first phase involves a rapid physicochemical adsorption of Cd onto cell wall binding sites, which are probably proteins and (or) polysaccharides. This is followed by a lag period and then a slow, steady intracellular uptake. This latter phase is energy dependent and may involve transport systems used to accumulate other divalent cations, such as Mn2+ and Ca2+. Some data indicate that Cd resistance, and possibly uptake, in algae and cyanobacteria is controlled by a plasmid-encoded gene(s). Although considerable information is available on Cd toxicity to, and uptake in fungi, further work is clearly needed in several areas. There is little information about Cd uptake by filamentous fungi, and even in yeasts, information on the specificity, kinetics, and mechanisms of Cd uptake is limited.(ABSTRACT TRUNCATED AT 400 WORDS)

Publication Types:

Review

PMID: 3089567 [PubMed - indexed for MEDLINE]

Strategies of response to copper, cadmium, and lead by a blue-green and a green alga.

Laube VM, McKenzie CN, Kushner DJ.

The toxic metal ions Cu2+, Cd2+, and Pb2+ inhibited growth of the green alga Ankistrodesmus braunii and the blue-green alga (Cyanobacterium) Anabaena, strain 7120. Some concentrations of Cu lysed Anabaena 7120 at early, but not late, stages of growth. The other metals inhibited growth without causing lysis. Adding the chelating agent nitrilotriacetic acid (NTA) did not reduce, and in some cases increased, metal toxicity to Anabaena 7120. This suggests that these metals do not act on this alga only in the ionic form. When Anabaena 7120 grew in a sublethal concentrations of Cu(NO3)2 (10(-5)M) most of the Cu was found outside the cell, in nonionic form. About half the Cd was found to be cell associated when these algae grew in the presence of 10(-5)M Cd(NO3)2. Ankistrodesmus braunii bound substantial amounts of both Cd and Cu when growing in their presence. At certain Cu levels, the amount bound per cell remained virtually constant during growth. In Cd, the amount bound per cell was highest at the beginning of growth and then fell. Cell-associated metals were found in both wall plus membrane and cytoplasmic fractions of A. braunii after mechanical lysis. When these algae grew over dialysis sacs containing sediment loaded with Cd or Cu, substantial amounts of these metals left the sediment and entered the algal cultures. They were found both cell associated and in the culture medium of A. braunii. In cultures of Anabaena 7120, Cd removed from the sediment was found in both cells and culture medium, but Cu was found almost entirely in the culture medium. The effects that bloom of such algae might have on the mobilization of these metals from sediments in natural waters are discussed.

PMID: 6783279 [PubMed - indexed for MEDLINE]

The effect of inorganic and organic mercury on growth kinetics of Nitzschia accicularis W. Sm. and Tetraselmis suecica Butch.

Mora B, Fabregas J.

Studies have been made on the toxicities of three inorganic (HgCl2, HgSO4, and NH2HgCl) and two organic (CH3HgCl and phenyl mercuric acetate (PMA)) mercury derivatives on planktonic algae (Nitzschia acicularis W. Sm. and Tetraselmis suecica Butch.) Growth kinetics and flourescence changes were used as criteria for assessing algal-metal responses. Methylmercury chloride was found to be the more toxic form, inhibiting growth of both species at levels of 0.025 ppm Hg. PMA inhibited Nitzschia at the same concentration. Inorganic forms prevent growth of the diatom at 0.15-0.20 ppm Hg. Addition of inorganic mercury at concentrations of 0.05 ppm Hg resulted in reduction of the lag phase, increase in exponential growth rate, or both. Increasing mercury concentrations caused a gradual increase in the lag phase in T. suecica and in N. acicularis only with mercuric sulphate. Populations recovered from this initial effect and started to grow. The effect of inoculum size on mercurial toxicity was tested. The higher concentrations of mercury that still permit growth restricted the chlorophyll fluorescence to the central cellular area and the cells appear slimmed. This effect is highest in concentrations that inhibit growth.

PMID: 6450629 [PubMed - indexed for MEDLINE]

Phallotoxin-visualization of F-actin in normal and chromium-poisoned Euglena cells.

Bassi M, Donini A.

The presence of F-actin in Euglena cells was revealed by the use of fluorescent delta-aminophalloin. In normal cells F-actin forms a web of fine filaments at the cell periphery and around the nucleus. In Cr-poisoned cells this pattern is completely altered, and F-actin is visible as a single strongly fluorescent band of various shape and location.

PMID: 6439420 [PubMed - indexed for MEDLINE]

Effects of aluminum on plasma membrane as revealed by analysis of alkaline band formation in internodal cells of Chara corallina.

Takano M, Shimmen T.

Department of Life Sciences, Faculty of Science, Himeji Institute of Technology, Harima Science Park City, Hyogo, Japan.

To study the mechanism of aluminum toxicity in plant cells, the effects of aluminum on alkaline band formation were analyzed in the internodal cells of Chara. After cells were treated with AlCl3, they were examined for their capacity to develop alkaline bands. Treating cells with AlCl3 medium at pH 4.5 completely inhibited alkaline band formation. When either CaCl2 or malic acid was added to the AlCl3 medium (pH 4.5), it did not produce an ameliorative effect, whereas addition of both CaCl2 and malic acid induced a significant ameliorative effect. It was found that treatment at pH 4.5 in the absence of AlCl3 strongly inhibited alkaline band formation. This inhibition by the low pH (4.5) treatment was effectively ameliorated by CaCl2. At higher pH (5.0), malic acid alone produced a significant ameliorative effect on aluminum inhibition of alkaline band formation, but CaCl2 did not. Recovery from aluminum inhibition was also studied. When cells treated with AlCl3 at pH 4.5 were incubated in artificial pond water, they could not recover the capacity to develop alkaline band. When either malic acid or CaCl2 was added to artificial pond water, cells recovered their alkaline band formation. It was concluded that one of the primary targets of aluminum is the plasma membrane and that aluminum affects the plasma membrane from the cell exterior at the beginning of the treatment (within 24 h). It was also suggested that the aluminum treatment impairs the HCO3- influx mechanism but not the OH- efflux mechanism.

PMID: 10462175 [PubMed - indexed for MEDLINE]

Zinc acclimation and its effect on the zinc tolerance of Raphidocelis subcapitata and Chlorella vulgaris in laboratory experiments.

Muyssen BT, Janssen CR.

Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Belgium. [email protected]

The effect of zinc acclimation of Raphidocelis subcapitata (syn. Selenastrum capricornutum) and Chlorella vulgaris on their sensitivity towards this metal was examined in a series of laboratory experiments. These two commonly used algal species were acclimated to 65 microg Zn/l and changes in zinc tolerance were monitored using standard growth inhibition tests. The chemically defined ISO medium was used as a control culture medium. Both species demonstrated a maximum increase in zinc tolerance of a factor of 3 after 100 days of acclimation. Shifts in the shape of the concentration-response curve due to acclimation were observed for R. subcapitata. Compared to non-acclimated algae, acclimated R. subcapitata exhibited higher growth rates in all zinc treatments as well as in the controls. This suggests that the use of ISO-medium results in sub-optimal growth due to zinc deficiency. These effects could not be demonstrated for C. vulgaris. The zinc tolerance of both species decreased significantly one week after returning the acclimated algae to control (ISO) medium. 72hEC50 values based on growth rate were two to four times higher than those calculated using biomass measurements. Algal toxicity test results, particularly if used for metal risk assessments, must not be conducted using nutrient deficient media.

PMID: 11680746 [PubMed - indexed for MEDLINE]

Acute toxicity of excess mercury on the photosynthetic performance of cyanobacterium, S. platensis--assessment by chlorophyll fluorescence analysis.

Lu CM, Chau CW, Zhang JH.

Department of Biology, Hong Kong Baptist University, Kowloon Tong, People's Republic of China.

Measurement of chlorophyll fluorescence has been shown to be a rapid, non-invasive, and reliable method to assess photosynthetic performance in a changing environment. In this study, acute toxicity of excess Hg on the photosynthetic performance of the cyanobacterium S. platensis, was investigated by use of chlorophyll fluorescence analysis after cells were exposed to excess Hg (up to 20 microM) for 2 h. The results determined from the fast fluorescence kinetics showed that Hg induced a significant increase in the proportion of the Q(B)-non-reducing PSII reaction centers. The fluorescence parameters measured under the steady state of photosynthesis demonstrated that the increase of Hg concentration led to a decrease in the maximal efficiency of PSII photochemistry, the efficiency of excitation energy capture by the open PSII reaction centers, and the quantum yield of PSII electron transport. Mercury also resulted in a decrease in the coefficients of photochemical and non-photochemical quenching. Mercury may have an acute toxicity on cyanobacteria by inhibiting the quantum yield of photosynthesis sensitively and rapidly. Such changes occurred before any other visible damages that may be evaluated by other conventional measurements. Our results also demonstrated that chlorophyll fluorescence analysis can be used as a useful physiological tool to assess early stages of change in photosynthetic performance of algae in response to heavy metal pollution.

PMID: 10819201 [PubMed - indexed for MEDLINE]

Physico-chemical characteristics and pollution level of Lake Nainital (U.P., India): role of macrophytes and phytoplankton in biomonitoring and phytoremediation of toxic metal ions.

Ali MB, Tripathi RD, Rai UN, Pal A, Singh SP.

Environmental Botany Laboratory, National Botanical Research Institute, Lucknow, India.

Lake Nainital is the sole source of drinking water for the local people and even to majority of tourists. In background of lake utility and its importance at national level, such study is essential which is focused on toxic metal pollution and current nutrient status of the lake and their magnification by algae and macrophytes. Study has shown that lake water is rich in nutrients which supports growth of many aquatic macrophytes and algal blooms. Besides, water is contaminated with metals like Cr, Cu, Fe, Mn, Ni, Pb and Zn. Concentration of some of them like Fe, Pb and Ni were higher than the recommended maximum permissible limits. Concentration of these metals were also found high in lake sediments. The level of metals amongst various components of lake varied considerably in different season. Plants and algae growing therein accumulated appreciable amount of metals and water roots of Salix being more efficient than others. High metal removing potential of these plants may be significant for biomonitoring studies and could be a useful phytoremediation technology to restore water quality by harvesting submerged and floating biomass inhabiting littoral zone of the lake.

PMID: 10576113 [PubMed - indexed for MEDLINE]

Physical-chemical and ecotoxicological evaluation of water based drilling fluids used in Italian off-shore.

Terzaghi C, Buffagni M, Cantelli D, Bonfanti P, Camatini M.

Dipartimento di Scienze dell'Ambiente e del Territorio, Milano, Italy.

In order to evaluate the effects on the marine ecosystem caused by an eventual discharge into sea of water based drilling fluids, as current legislation allows, chemical and ecotoxicological analyses were performed on the most common drilling muds and products used in Italian off-shore activities. The chemical analysis on drilling fluids involved the leaching test and the measurement of total content of heavy metals, whereas biodegradation tests were performed on the products used in mud's formulations. As for ecotoxicological evaluation, two marine organisms, the crustacean Artemia salina and the diatom Phaeodactylum tricornutum, were selected to determine the LC50 and the EC50 respectively.

PMID: 9839404 [PubMed - indexed for MEDLINE]

The ecotoxicity and the biodegradability of lactic acid, alkyl lactate esters and lactate salts.

Bowmer CT, Hooftman RN, Hanstveit AO, Venderbosch PW, van der Hoeven N.

Department of Environmental Toxicology, TNO Nutrition and Food Research Institute, Delft, The Netherlands.

The ecotoxicity of lactic acid, its alkyl esters and selected metal salts was studied experimentally with the micro alga Selenastrum capricornutum, the crustacean Daphnia magna and the fish species Brachydanio rerio and Pimephales promelas. In addition, the biodegradation of lactate esters was also studied. The aim of the study was to provide predicted environmental data for additional alkyl homologues and metal salts. The ecotoxicity data are evaluated by means of Structure Activity Relations (SAR), using literature data on a non-polar narcotic mechanism of toxicity as a baseline for comparison. Lactate salts were evaluated by comparison to the toxicity of the metal ion. For the fish and D. magna, it was evident that methyl, ethyl, propyl and to a lesser extent butyl lactate were slightly more toxic in comparison to baseline non-polar narcotic toxicity data. The toxicity tests carried out with lactate-salts demonstrated clearly that the toxicity in standard tests is only determined by the associated cation and not by the lactate part. Lactic acid and its alkyl esters were degraded for more than 60% in the ready biodegradability tests and from the data presented, it is evident that the majority of alkyl lactates are readily biodegradable. The results presented in this study indicate that alkyl lactate esters show some differences in their ecotoxicity when compared to non polar narcotic compounds in but that these differences are generally small. When aquatic toxicity is considered together with their rapid tendency to biodegrade, it is concluded that lactate esters show generally favourable environmental characteristics.

PMID: 9734323 [PubMed - indexed for MEDLINE]

Response to heavy metals in organisms-I. Excretion and accumulation of physiological and non physiological metals in Euglena gracilis.

Albergoni V, Piccinni E, Coppellotti O.

PMID: 6108179 [PubMed - indexed for MEDLINE]

Environmental factors that influence the toxicity of heavy metal and gaseous pollutants to microorganisms.

Babich H, Stotzky G.

Publication Types:

Review

PMID: 7000442 [PubMed - indexed for MEDLINE]

A review of the environmental and mammalian toxicology of nitrilotriacetic acid.

Anderson RL, Bishop WE, Campbell RL.

This article provides a review of available information on the chemistry, environmental toxicology, and mammalian toxicology of nitrilotriacetic acid (NTA). The ability of NTA to chelate metal ions such as Mg++ and Ca++ into water soluble complexes makes NTA useful as an additive to boiler water, as a builder in laundry detergents, and as a stabilizer in textile, paper, and pulp processing. Environmental fate studies show NTA biodegrades in wastewater treatment plants, in natural waters, and in soils under a wide variety of conditions. Studies on the environmental effects of NTA indicate that no adverse effects occur in treatment plants or receiving waters at anticipated levels. Monitoring programs have established that only low steady-state concentrations of NTA occur in natural waters as a result of NTA usage. In mammalian systems, NTA is not metabolized and is excreted rapidly by filtration in the kidney. No reproductive, teratogenic, or adverse bone effects have been observed at highly exaggerated doses. In numerous genotoxicity assay systems, both in vivo and in vitro, NTA is nongenotoxic. Chronic oral exposure of rodents to high doses of NTA is associated with tumorigenicity in, and restricted to, the urinary tract. The urinary tract tumors are the consequence of chronic toxicity that is caused by changes in Zn and Ca distributions between the urinary tract tissues and urine at high doses of NTA. Thresholds for the effects of NTA on Zn and Ca distributions are 10(5) to 10(6) greater than the possible maximum human exposure resulting from the low levels of NTA that are known to occur in the environment.

Publication Types:

Review

PMID: 3899518 [PubMed - indexed for MEDLINE]

Effects of power plant coal pile and coal waste runoff and leachate on aquatic biota: an overview with research recommendations.

Hall LW Jr, Burton DT.

Publication Types:

Review

PMID: 6756794 [PubMed - indexed for MEDLINE]

Reclamation with cyanobacteria: toxic effect of mercury contaminated waste soil on biochemical variables.

Mishra BB, Nanda DR.

Department of Botany, College of Basic Science and Humanities, Orissa University of Agriculture and Technology, Bhubaneswar, India.

During an attempt to decrease the toxicity of industrial waste (soil) from a chloralkali factory by blue-green algae, the effect of the waste soil mixed in varying proportions with garden soil, on biochemical variables was studied. The nucleic acid, protein and free amino acid content of the algae decreased significantly with increasing time and waste soil concentration. The algae accumulated a substantial amount of mercury from the medium depending on the duration of algal growth and waste soil concentration. An increase in RNA/DNA and a decrease in the ratio of protein/RNA and protein/free amino acids was observed.

PMID: 9693887 [PubMed - indexed for MEDLINE]

Toxic action of copper on the membrane system of a marine diatom measured by flow cytometry.

Cid A, Fidalgo P, Herrero C, Abalde J.

Departamento de Biologia Celular y Molecular, Universidade da Coruna, Spain.

Flow cytometric measurements were used to investigate the toxic action of copper on some Phaeodactylum tricornutum membrane systems. Throughout the time of metal exposure, the percentage of viable cells decreased as copper concentration increased. The forward scatter signal increased as a result of copper exposure. After 72 h of metal exposure, cultures with 0.5 and 1 mg l-1 of copper showed an important increase in the peroxidase activity in comparison with control cells. Cells cultured with copper presented alterations in the membrane potential, increasing as copper concentration increased, after 96 h of metal exposure. Results obtained in this work showed that copper induced a degenerative process in P. tricornutum cells, closely related with alternations or disorders in membrane systems.

PMID: 8875052 [PubMed - indexed for MEDLINE]

Light intensity influences chromium bioaccumulation and toxicity in Scenedesmus acutus (Chlorophyceae).

Gorbi G, Corradi MG, Invidia M, Bassi M.

Department of Environmental Sciences, University of Parma, Parma, I-43100, Italy.

The influence of light intensity on chromium uptake was studied in two strains of the freshwater unicellular alga Scenedesmus acutus (Chlorophyceae) having different sensitivity to Cr poisoning and light intensity. The two strains were subjected to different Cr treatments at 3000 and 80 lux. Cr toxicity was assessed by algal growth rate, recovery test, methylene blue staining, and determination of photosynthetic activity. After 2 and 4 days of treatment, bioaccumulated chromium, cell dry mass, and protein and carbohydrate contents were also assessed. When the algae were treated at 3000 lux, different bioaccumulation patterns were obtained when Cr content was related to dry mass, cell number, or protein content. A direct relationship between Cr content and cell mortality was observed only when the amount of Cr was related to protein content. In both strains Cr uptake was slower in subdued light, suggesting that it is linked to energy-dependent processes. The difference between the strains in sensitivity to Cr poisoning was also evident in subdued light.

PMID: 11161675 [PubMed - indexed for MEDLINE]

Influence of cellular density on determination of EC(50) in microalgal growth inhibition tests.

Moreno-Garrido I, Lubian LM, Soares AM.

Instituto de Ciencias Marinas de Andalucia, Poligono Rio San Pedro, s/n., Puerto Real, Cadiz, 11510, Spain.

Growth inhibition tests for copper were carried out on four marine microalgal species: Chlorella autotrophyca, Nannochloris atomus (Chlorophyceae), Phaeodactylum tricornutum (Bacillariophyceae), and Isochrysis aff. galbana (Primnesiophyceae). The test initial cellular densities were reduced to 50 and 10% from the recommended initial cellular density in most of standardized assays. OECD test protocol (originally described for freshwater) was adapted for seawater. The EC(50) values were reduced when initial cellular density decreased. The green algae used in this study exhibited lower sensitivity than P. tricornutum and quite lower than I. aff. galbana. The latter species was found to be very sensitive to copper. The concept of cellular toxic quote (amount of toxic per cell) is defined in order to improve the results of toxicity tests. Copyright 2000 Academic Press.

PMID: 11023688 [PubMed - indexed for MEDLINE]

Derivation of predicted No-effect concentrations for lindane, 3, 4-dichloroaniline, atrazine, and copper.

Girling AE, Tattersfield L, Mitchell GC, Crossland NO, Pascoe D, Blockwell SJ, Maund SJ, Taylor EJ, Wenzel A, Janssen CR, Juttner I.

Shell Research Limited, United Kingdom.

Environmental risk assessment is a key feature of regulations controlling the placing of new, and the maintenance of existing, chemicals products in the market place. For example, European Commission Directive 93/67/EC on Risk Assessment for New Notified Substances and Commission Regulation (EC) No. 1488/94 on Risk Assessment for Existing Substances requires that risk assessments be carried out for new and existing substances in the European Community. The process of environmental risk assessment seeks to determine the balance of probability of species and communities being damaged by chemical releases. The process relies upon a valid estimation of a predicted environmental concentration (PEC) in relevant environmental compartments and a predicted no effect concentration (PNEC) below which the organisms present in that compartment are unlikely to be significantly affected. If the PEC exceeds the PNEC there is a potential for damaging effects to occur. This article focuses on the determination of PNECs for risk assessment. Methods for determining a PNEC described in OECD Monograph 26 (1989, Report of the OECD Workshop on Ecological Effect Assessment, Paris, France, have been applied to data derived for the four chemicals lindane, 3,4-dichloroaniline, atrazine, and copper in a series of collaborative research projects funded by the European Commission. Copyright 2000 Academic Press.

PMID: 10831327 [PubMed - indexed for MEDLINE]

Development of methods for evaluating toxicity to freshwater ecosystems.

Girling AE, Pascoe D, Janssen CR, Peither A, Wenzel A, Schafer H, Neumeier B, Mitchell GC, Taylor EJ, Maund SJ, Lay JP, Juttner I, Crossland NO, Stephenson RR, Persoone G.

Shell Research Limited, Sittingbourne Research Centre, United Kingdom.

This article presents a summary of a collaborative research program involving five European research groups, that was partly funded by the European Commission under its Environmental Research Program. The objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at Level 2 of the Risk Evaluation Scheme for the Notification of Substances as required by the 7th Amendment to EC Directive 79/831/EEC. Currently only a very limited number of test methods have been described that can be used for this purpose and these are based on an even smaller number of test species. Tests based upon algae (Chlamydomonas reinhardi, Scenedesmus subspicatus, and Euglena gracilis), protozoa (Tetrahymena pyriformis), rotifera (Brachionus calyciflorus), crustacea (Gammarus pulex), and diptera (Chironomus riparius) were developed. The tests encompassed a range of end points and were evaluated against four reference chemicals: lindane, 3, 4-dichloroaniline (DCA), atrazine, and copper. The capacity of the tests to identify concentrations that are chronically toxic in the field was addressed by comparing the effects threshold concentrations determined in the laboratory tests with those determined for similar and/or related species and end points in stream and pond mesocosm studies. The lowest no-observed-effect concentrations (NOEC), EC(x), or LC(x) values obtained for lindane, atrazine, and copper were comparable with the lowest values obtained in the mesocosms. The lowest chronic NOEC determined for DCA using the laboratory tests was approximately 200 times higher than the lowest NOEC in the mesocosms. Copyright 2000 Academic Press.

PMID: 10648133 [PubMed - indexed for MEDLINE]

In vitro populations of rotifer Brachionus plicatilis Muller demonstrate inhibition when fed with copper-preaccumulating microalgae.

Moreno-Garrido I, Lubian LM, Soares AM.

Instituto do Ambiente e Vida, Departamento Zoologia, Universidade de Coimbra, Portugal.

Four marine microalgal species (Chlorella autotrophyca, Nannochloropsis gaditana, Tetraiselmis chuii, and Isochrysis aff. galbana) were exposed for 24 h to 1 mg L(-1) dissolved copper and then transferred to fresh medium. After that, a group of 10 neonate rotifers were fed with these four microalgal species. The levels of accumulated copper in cellular concentrations of the microalgae were checked, with the result of around 40% of original concentration, with the exception of I. aff. galbana (25% of original concentration). In all cases, cells with preaccumulated metal caused a delay of 1 or 2 days in populational development of rotifers (increase in "lag phase"). The microalgae that were not fed to rotifers (disposed in parallel series) did not significantly transfer metal to the medium after the first day.

PMID: 10571470 [PubMed - indexed for MEDLINE]

Monitoring of labile zinc in cultures of Skeletonema costatum using a salt groundwater.

Schintu M, Koussih L, Chevolot L, Amiard JC, Robert JM.

Dipartimento di Igiene e Sanita Pubblica, Universita di Cagliari, Via Porcell 4, Cagliari, 09100, Italy.

Labile Zn concentration was monitored by differential pulse anodic stripping voltammetry (DPASV) throughout the exponential growth phase of the marine diatom Skeletonema costatum (Grev.) Cleve. Algal blooms were induced both under natural conditions and in laboratory experiments using a salt groundwater (salinity 33) from the Bay of Bourgneuf, northwest coast of France. Salt groundwater is a very complex medium containing high concentrations of dissolved organic matter and other trace metal adsorbents, such as phosphate, iron oxyhydroxides, and manganese and silicon oxides, which can bind metal ions, reducing their availability and toxicity to algae. Besides metal uptake by algae and complexation of Zn by algal exudates, the rapid decrease in the labile Zn concentration during the algal blooms was ascribed mainly to the adsorption or coprecipitation of Zn ion onto freshly formed iron hydroxides. Copyright 1999 Academic Press.

PMID: 10090809 [PubMed - indexed for MEDLINE]

Amado Filho GM, Karez CS, Andrade LR, Yoneshigue-Valentin Y, Pfeiffer WC.

Jardim Botanico do Rio de Janeiro/IBAMA, Brazil. [email protected]

Seaweed species from a coastal area contaminated by heavy metals (Sepetiba Bay) in Rio de Janeiro State (Brazil) presented different levels of Zn concentrations. In some species the levels were 20 times higher than that from a noncontaminated area. The present study was undertaken to investigate the capability of different species to tolerate and accumulate zinc. For this purpose six species, Ulva lactuca, Enteromorpha flexuosa, Padina gymnospora, Sargassum filipendula, Hypnea musciformis, and Spyridia filamentosa, were cultivated under laboratory semistatic conditions in five Zn concentrations in seawater, 10, 20, 100, 1000, and 5000 micrograms.liter-1 for a period of 21 days. All species died at 5000 micrograms.liter-1 of Zn, two species (U. lactuca and E. flexuosa) died at 1000 micrograms.liter-1, and one, H. musciformis, died with 100 micrograms.liter-1. The lowest concentration of Zn that presented growth inhibition in the six species was 20 micrograms.liter-1. The brown alga P. gymnospora presented the highest accumulation level of Zn, and H. musciformis the lowest level. The results of tolerance and accumulation under laboratory conditions, associated with field results, indicate the species of Padina and Sargassum as the best species for monitoring heavy metals in tropical coastal areas, and the potential use of their biomass to remove heavy metals from wastewaters.

PMID: 9378088 [PubMed - indexed for MEDLINE]

Polarography as a tool in peptide and protein analysis: studies on metal-chelating substances induced by cadmium in the algae Pheodactylum tricornutum and the graminae Agrostis capillaris.

Nyberg S, Zhou L.

Department of Systems Ecology, Stockholm University, Sweden.

Methods to determine characteristics and quantities of metal-binding substances are needed in order to identify phytochemical systems for use in agriculture and waste treatment. A metal-binding polypeptide (phytochelatin) was prepared by liquid chromatography from the algae Pheodactylum tricornutum and roots of the graminae Agrostis capillaris after exposure to cadmium. Polarographic (voltammetric) analysis indicated binding of cadmium by the polypeptide at different stabilities. No catalytic hydrogen peak at -1.7 V appeared in the polarogram of plant and algae metal-binding substance, but did appear in the polarogram of the metal-chelating protein metallothionein. In all polarograms, two significant peaks were detected. One at approximately -520 mV probably represents the reduction of single cadmium-sulfur bonds, and one at -930 mV the reduction of cadmium-thiolate complexes. A dose-response relationship between cadmium concentration and peak current at -930 mV was observed after exposure of roots of Agrostis at 5 and 10 microM.

PMID: 8575359 [PubMed - indexed for MEDLINE]

Physiology of carbon assimilation in a green alga during exposure to and recovery from cadmium.

Thompson PA, Couture P.

INRS-Eau, Institut national de la recherche, Sainte-Foy, Quebec, Canada.

The flow of recently photoassimilated carbon into proteins, lipids, and polysaccharides was studied with asynchronous Selenastrum capricornutum populations during exposure to and recovery from 30 and 100 micrograms Cd.liter-1. During a 48-hr exposure to Cd, increases in Cd cell quotas were accompanied by nearly exponential decreases in growth and photosynthesis and by a disruption of the pattern of carbon allocation to macromolecules. In particular, relative to the control, the cells exposed to Cd allocated a higher percentage of carbon to the synthesis of polysaccharides. After the addition of EDTA (recovery period), Cd cell quotas decreased and growth recovery was accompanied by the recovery of photosynthesis and by an enhanced flow of carbon to lipids and proteins. The results of the experiment suggest that the measurement of the distribution of recently photoassimilated carbon into macromolecules has potential for monitoring the effects of toxic effluent discharges on primary producers.

PMID: 7504615 [PubMed - indexed for MEDLINE]

Chromium toxicity on two linked trophic levels. I. Effects of contaminated algae on Daphnia magna.

Gorbi G, Corradi MG.

Istituto di Ecologia, Universita di Parma, Italy.

The effects of feeding Daphnia magna on algae (Scenedesmus acutus) pretreated with different concentrations of Cr(VI) were studied. A positive effect on growth and newborn production rate was observed in the daphnids fed on algae exposed to 1 mg/liter Cr(VI). Fecundity and growth were drastically reduced in daphnids fed on algae exposed to 10 mg/liter Cr(VI). Since the algae, cultured in the presence of these two Cr(VI) concentrations, supplied daphnids with similar amounts of chromium, the observed effects on the population dynamics of D. magna were attributed more to alterations of the nutritional value of the algal food, due to the Cr treatment, than to a toxic effect of the metal.

PMID: 7682919 [PubMed - indexed for MEDLINE]

Chromium toxicity on two linked trophic levels. II. Morphophysiological effects on Scenedesmus acutus.

Corradi MG, Gorbi G.

Istituto di Botanica, Universita di Parma, Italy.

The morphophysiological effects of Cr(VI) on Scenedesmus acutus were studied by light and fluorescence microscopy. Axenic cultures of S. acutus were grown in the presence of 1, 5, and 10 mg/liter of Cr(VI) supplied as K2Cr2O7. It was found that Cr(VI) inhibits cell proliferation and the formation of coenobia. It also induces alterations in cell morphology; depending on the dose, it induces the formation of multicellular plurinucleated aggregates or the appearance of large uninucleated cells. By using methylene blue staining, it was possible to identify the algal cells that had undergone irreversible damage.

PMID: 7682920 [PubMed - indexed for MEDLINE]

Study of dependency between culture growth and photosynthetic efficiency measured by fluorescence induction in Selenastrum capricornutum inhibited by copper.

Cvetkovic AD, Samson G, Couture P, Popovic R.

Departement de Chimie, Universite du Quebec a Montreal, Canada.

Fluorescence parameters were reported earlier to be reliable indicators in the determination of heavy metal toxicity in algal cultures (Samson and Popovic, 1988). In this report, the effects of copper on Selenastrum capricornutum culture growth and photosynthetic efficiency were studied at different copper concentrations. By using the complementary area of variable fluorescence kinetics and the cell counting method, we determined the level of toxicity at different copper concentrations and the ability of algal populations to adapt to inhibitory effects. Algae exposed to copper concentrations higher than 0.5 mg/liter were incapable of recovering biochemical and physiological processes related to photosynthesis after 96 hr. A recovery process in algal culture intoxicated with 0.5 mg/liter was revealed only by fluorescence induction phenomena. Here, the authors justify the use of fluorescence induction parameters in the investigation of copper stress effects on algal populations and their short-term adaptation phenomena.

PMID: 1769346 [PubMed - indexed for MEDLINE]

Employment of CEPEX enclosures for monitoring toxicity of Hg and Zn on in situ structural and functional characteristics of algal communities of River Ganga in Varanasi, India.

Rai LC, Singh AK, Mallick N.

Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, India.

Effects of Hg and Zn on in situ nitrogen fixation, autotrophic index, pigment diversity, 14CO2 uptake, and change in algal community structure of Ganges water have been studied for the first time using CEPEX chambers in aquatic ecosystem of India. A concentration-dependent decrease in in situ nitrogenase activity of Ganges water with Hg and Zn has been noticed. No ethylene production was observed at 0.8 microgram/ml of Hg. However, an increase in the autotrophic index was observed in CEPEX enclosures treated with Hg and Zn. The AI value was maximum at 0.8 microgram/ml Hg after an incubation of 15 days. An increase in pigment diversity also followed the pattern of AI with the test metals used. Inhibition of 14CO2 uptake of phytoplankton of Ganges water was maximum at 0.8 microgram/ml Hg (79%) followed by Zn (69%). Carbon fixation showed an increase for 1 hr, after which no appreciable change was noticed. Maximum inhibition of algal number was observed at 0.8 microgram/ml Hg followed by 8.0 micrograms/ml of Zn in the CEPEX chamber. Members of Chlorophyceae showed more tolerance than Cyanophyceae and Bacillariophyceae. The filamentous forms were more tolerant to Hg and Zn. In contrast, unicellular forms were more sensitive to Hg. The test of significance (ANOVA) showed that metal-induced variations in pigment diversity, the autotrophic index, and the 14CO2 uptake were highly significant (P less than 0.001).

PMID: 1980458 [PubMed - indexed for MEDLINE]

Influence of inorganic and triethyl lead on nuclear migration and ultrastructure of Micrasterias.

Meindl U, Roderer G.

Institut fur Pflanzenphysiologie, Universitat Salzburg, Austria.

Developing cells of three strains of the desmidiacean alga Micrasterias were treated with inorganic and triethyl lead and examined by light and electron microscopy. In the concentration range 12 to 30 microM, triethyl lead disturbed normal development of the algae, caused changed dictyosomal ultrastructure, disturbed the formation of the secondary cell wall, and caused accumulation of lipid material. Cell multiplication was strongly inhibited between 5 and 30 microM TriEL in Micrasterias denticulata, showing complete inhibition at 15 microM and above. In addition, nuclear migration of developing Micrasterias cells was selectively disturbed by growth-inhibiting concentrations of TriEL, resulting in unusual positioning of the post-telophase nucleus. Although inorganic lead proved to be much more poisonous to Micrasterias cells than TriEL and caused bursting of the cells even at the low concentration of 3 microM it did not affect nuclear migration. Electron microscopic observations revealed a complete disassembly of the post-telophase system of microtubules which is involved in nuclear migration by TriEL, but no detectable effect on the isthmus system of microtubules which anchors the nucleus in the isthmus. It is concluded that the disturbance of nuclear migration in Micrasterias by TriEL was due to the selective disassembly of the involved microtubule system.

PMID: 2338065 [PubMed - indexed for MEDLINE]

Population consequences of cadmium toxicity in soil microarthropods.

van Straalen NM, Schobben JH, de Goede RG.

Department of Ecology and Ecotoxicology, Free University, Amsterdam, The Netherlands.

Chronic toxicity experiments were performed using the collembolan Orchesella cincta (L.) and the oribatid mite Platynothrus peltifer (Koch), which were exposed to various levels of cadmium in the food (green algae). Experimental results were combined with life-history information to obtain realistic estimates of the intrinsic rate of population increase and its sensitivity to Cd stress. Chronic LC50 values for dietary exposure to Cd were estimated as 1.60 mumol/g for O. cincta and 3.18 mumol/g for P. peltifer. No-observed-effect concentrations (NOECs) for growth and reproduction were 0.042 mumol/g for O. cincta and 0.026 mumol/g for P. peltifer. The main effects of Cd were, however, different in each species. In O. cincta, Cd affected primarily female growth, without a direct effect on reproduction; in P. peltifer, the effect was primarily on reproduction. Uptake of Cd was higher in P. peltifer than in O. cincta, and caused a loss of zinc in the former species. As a consequence of their differing physiological responses to Cd, mites and collembolans also reacted differently in their population growth rates. The capacity for population increase of mites appeared to be rather sensitive to Cd, while collembolans were able, to some extent, to maintain their capacity for increase, in spite of toxic effects at the individual level. These results may contribute to developing ecotoxicological theory for the population consequences of toxic action in species with diverging life histories. Soil microarthropods may be suitable test organisms for evaluating the risk of chemicals to the soil ecosystem.

PMID: 2737113 [PubMed - indexed for MEDLINE]

Use of algal fluorescence for determination of phytotoxicity of heavy metals and pesticides as environmental pollutants.

Samson G, Popovic R.

Centre de Recherche en Photobiophysique, Universite du Quebec a Trois-Rivieres, Canada.

The phytotoxicity of heavy metals and pesticides was studied by using the fluorescence induction from the alga Dunaliella tertiolecta. The complementary area calculated from the variable fluorescence induction was used as a direct parameter to estimate phytotoxicity. The value of this parameter was affected when algae were treated with different concentrations of mercury, copper, atrazine, DCMU, Dutox, and Soilgard. The toxic effect of these pollutants was estimated by monitoring the decrease in the complementary area, which reflects photosystem II photochemistry. Further, the authors have demonstrated the advantage of using the complementary area as a parameter of phytotoxicity over using variable fluorescence yield. The complementary area of algal fluorescence can be used as a simple and sensitive parameter in the estimation of the phytotoxicity of polluted water.

PMID: 3229381 [PubMed - indexed for MEDLINE]

Toxicity of nickel and silver to Nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids.

Rai LC, Raizada M.

Laboratory of Algal Biology, Banaras Hindu University, Varanasi, India.

Exposure of Nostoc muscorum to different concentrations of Ni and Ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (K+, Na+). In an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (L-cysteine and L-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for Ag than Ni. However, metal-induced inhibition of growth and carbon fixation was equally ameliorated by methionine. But the level of protection by cysteine was quite different, i.e., 27% for Ni and 22% for Ag. Protection of metal toxicity in N. muscorum by amino acids lends further support to self-detoxifying ability of cyanobacteria because they are known to synthesize all essential amino acids.

PMID: 3123194 [PubMed - indexed for MEDLINE]

On the toxic effects of tetraethyl lead and its derivatives on the chrysophyte Poterioochromonas malhamensis. VII. Protective action of thiol compounds, vitamins, trace elements, and other agents.

Roderer G.

The influence of 45 different substances on the growth inhibiting effects of triethyl lead chloride (TriEL) in cultures of the unicellular alga Poterioochromonas malhamensis was studied. Ten thiol or disulfide compounds, 9 vitamins, 12 trace elements, 14 miscellaneous agents, and 9 combinations of these agents were tested. The agents were applied to the algal cultures in three different concentrations simultaneously with 10 microM TriEL and incubated for 72 hr. While none of the tested thiol and disulfide compounds remarkably protected the algae from TriEL toxicity, two vitamins (tocopheryl acetate, ascorbic acid), one trace element (zinc), adenosine-5'-triphosphate Na2 salt, cyclic AMP, and concanavalin A as well as combinations of some of these agents were found to suppress markedly the growth inhibiting effects of TriEL. Zinc was the most effective agent; it increased algal growth in TriEL-treated cultures by about 70 times as compared with cultures containing TriEL alone. A combination of 10 essential trace elements was even more protective and almost completely suppressed TriEL toxicity. In contrast to this, some of the other agents potentiated the toxic effects of TriEL (e.g., magnesium, molybdenum, caffeine, deuteriumoxide, chlorpromazine, dimethylsulfoxide) in the tested concentration ranges. The most protective agents Zn, VitC, and VitE did not prevent the inhibitory effects of TriEL on microtubule (MT) assembly in vitro, suggesting that their in vivo protection is based on mechanisms other than direct protecting MTs from the attack of the lead compound. Zn had no direct influence on the stability and half life of TriEL in the growth medium. The lack of protection found by the thiol compounds used suggests that most probably general thiol interaction of TriEL is not its major toxic mechanism of action. It is postulated that the protective action of Zn, VitE, and VitC is directly or indirectly mediated by suppression of TriEL-induced peroxidation processes in the poisoned algae. The protective agents found provide a basis for further screening experiments in order to test their "therapeutic" potency in experimental animals poisoned with organolead.

PMID: 3720621 [PubMed - indexed for MEDLINE]

The use of cohorts and populations in chronic toxicity studies with Daphnia magna: a cadmium example.

van Leeuwen CJ, Luttmer WJ, Griffioen PS.

Two semistatic life table experiments with Daphnia magna were carried out on reconstituted and Lake IJssel water. The "nontoxic concentrations" for cadmium with respect to the intrinsic rate of natural increase, derived from age-specific survival and fecundity were 1 and 3.2 micrograms/liter, respectively. Body length appeared to be a sensitive parameter. A third intermittent-flow experiment was started with small, exponentially growing populations. These populations had a stable age distribution, were composed of cohorts of different ages and showed an almost perfect logistic growth. Cadmium was shown to reduce the upper numerical limit (carrying capacity) for D. magna and was inversely related to this parameter: log Y = 2.85 -0.20 log [Cd]; r = -0.99. A "nontoxic concentration" could not be established. Based on the "background" concentration of cadmium, a freshwater quality criterion of 0.1 microgram/liter is proposed. The results are used to discuss several shortcomings of the current methods. Finally it is stated that the introduction of the concepts of population dynamics in reproduction tests with D. magna is a realistic step towards ecotoxicology.

PMID: 3987588 [PubMed - indexed for MEDLINE]

Interest of dynamic tests in acute ecotoxicity assessment in algae.

Jouany JM, Ferard JF, Vasseur P, Gea J, Truhaut R, Rast C.

Sorption of toxics by algae may be important and occurs very early. Thus, a decrease of the experimental toxic concentrations in the medium results in understating toxicity when tests are conducted under static conditions. In this work, two different methods of exposure of algae (Chlorella vulgaris) are studied, the static test and the pseudodynamic test. Acute effects (biological and analytical effects) of inorganic compounds (Cu2+, Cd2+, Pb2+, Cr6+) have been evaluated for 96 hr of exposure; in each case, IC50 is much lower in the dynamic condition than in the static one. The percentage of reduction varies from 55 to 75% after 96 hr. Accumulation of metal by chlorellae is greater when testing by the pseudodynamic way, with Cu2+ and Pb2+. But in the case of Cd2+ and Cr6+, the concentration factors are similar in the two kinds of exposure. These results point out the advantage of the pseudodynamic test, of which the methodology is very easy, for a more realistic assessment of acute ecotoxicity in these organisms.

PMID: 6851933 [PubMed - indexed for MEDLINE]

Observations with Thalassiosira rotula (Meunier) on the toxicity and accumulation of cadmium and nickel.

Dongmann G, Nurnberg HW.

Cadmium and nickel toxicity thresholds based on generation time, maximum cell density, and chain length as toxicity indicators were evaluated from batch cultures of the marine diatom Thalassiosira rotula in nutrient-enriched seawater as substrate. Nickel toxicity is about an order of magnitude or more higher than cadmium toxicity. The toxicity thresholds decrease with increasing illumination and are not significantly affected by 10 mumol/liter EDTA. From the metal accumulation determined by voltammetry average maximum uptakes of 90 micrograms Ni/g DW and 600 micrograms Cd/g DW were determined.

PMID: 7169045 [PubMed - indexed for MEDLINE]

Toxicity and accumulation studies of cadmium (Cd2+) with freshwater organisms of different trophic levels.

Canton JH, Slooff W.

PMID: 7067648 [PubMed - indexed for MEDLINE]

The effects of cadmium-accumulated Chlorella on the reproduction of Moina macrocopa (Cladocera).

Hatakeyama S, Yasuno M.

PMID: 7297472 [PubMed - indexed for MEDLINE]

Cadmium IC50 determination on Chlorella vulgaris involving different parameters.

Truhaut R, Ferard JF, Jouany JM.

PMID: 7439092 [PubMed - indexed for MEDLINE]

Alterations of proliferating microorganisms by flow cytometric measurements after heavy metal intoxication.

Hutter KJ, Oldiges H.

PMID: 6155249 [PubMed - indexed for MEDLINE]

Interest of the experimental trophic chains as ecotoxicological models for the study of the ecosystem contaminations.

Ribeyre F, Boudou A, Delarche A.

PMID: 583409 [PubMed - indexed for MEDLINE]

Comparative studies on trace metal levels in marine biota. III. Typical levels and accumulation of toxic trace metals in muscle tissue and organs of marine organisms from different European seas.

Stoeppler M, Nurnberg HW.

PMID: 535554 [PubMed - indexed for MEDLINE]

Effects of acidification on metal availability to aquatic biota, with special reference to filamentous algae.

Stokes PM, Bailey RC, Groulx GR.

A survey of 34 shield lakes in Ontario and Quebec, pH 4.4 to 7.1, was made to evaluate which metals should be considered of concern as a risk to aquatic biota or consumers when lakes are acid stressed. A set of predictions, concerning the mobilization by man, the mobility, the chemical speciation, and the toxicity or bioaccumulation of metals in acid-stressed waters, were used as a basis for designing the study and organizing the results. Attached algae were used as biomonitors to assess metal bioavailability. The study concluded that zinc, lead, aluminum, and mercury were of concern in acid-stressed lakes, while the situation for manganese was unresolved, and cadmium was not studied. Nickel and copper were of concern only when a point source was involved. The study also concluded that the attached algal community had some value as a biomonitor, for metals in acid-stressed as well as metal-polluted surface waters.

PMID: 4076097 [PubMed - indexed for MEDLINE]

The pollution status and the toxicity of surface sediments in Izmit Bay (Marmara Sea), Turkey.

Tolun LG, Okay OS, Gaines AF, Tolay M, Tufekci H, Kiratli N.

TUBITAK, Marmara Research Center, Energy Systems and Environmental Research Institute, Kocaeli, Turkey.

Izmit Bay is one of the most polluted and populated enclosed sea in Turkey. It has been the centre of industrial activities for the last 30 years. Seven major sources enter the bay waters along the north coastline of the bay. This investigation forms part of continuing ecotoxicology studies in the Izmit Bay designed to constrain and minimise the pollution caused by flourishing industry and a growing population. Sediments sampled from the mouths of the major discharges of Izmit Bay were analysed for their organic carbon, total polycyclic aromatic hydrocarbon (t-PAH) and trace inorganic element (Cd, Al, As, Pb, Hg and Cu) contents and compared with those found in the sediments from the reference station in the outer bay (in the Marmara Sea). The toxicity of sediments was determined in the bulk and elutriate samples by using algal (Phaeodactylum tricornutum) batch bioassays. Chemical data showed that the sediments collected from the inner sites of the bay have been contaminated with Cd, Hg, As and PAHs. Organic carbon contents were also found higher. All the major industrial discharges into the bay are now biologically treated but bioassays performed with bulk sediments revealed that the recent sediments are toxic to the microalgae throughout the bay. The results are consistent with the previous toxicity studies performed with the industrial discharges.

PMID: 11341701 [PubMed - indexed for MEDLINE]

Necessity of toxicity assessment in Turkish industrial discharges (examples from metal and textile industry effluents).

Sponza DT.

Environmental Engineering Department, Engineering Faculty, Doku Eylul University, Izmir, Turkey. [email protected]

Toxicity of some organic and inorganic chemicals to microorganisms is an important consideration in assessing their environmental impact against their economic benefits. Microorganisms play an important role in several environmental processes, both natural and engineered. Some organic and inorganics at toxic levels have been detected in industrial discharges resulting in plant upsets and discharge permit violations. In addition to this, even though in some cases the effluent wastewater does not exceed the discharge limits, the results of toxicity tests show potential toxicity. Toxicity knowledge of effluents can benefit treatment plant operators in optimising plant operation, setting pre-treatment standards, and protecting receiving water quality and in establishing sewer discharge permits to safeguard the plant. In the Turkish regulations only toxicity dilution factor (TDF) with fish is part of the toxicity monitoring program of permissible wastewater discharge. In various countries, laboratory studies involving the use of different organisms and protocol for toxicity assessment was conducted involving a number of discharges. In this study, it was aimed to investigate the acute toxicity of textile and metal industry wastewaters by traditional and enrichment toxicity tests and emphasize the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications and give an idea whether there is potential toxicity or growth limiting and stimulation conditions. Different organisms were used such as bacteria (Floc and Coliform bacteria) algae (Chlorella sp.). fish (Lepistes sp.) and protozoan (Vorticella sp.) to represent four tropic levels. The textile industry results showed acute toxicity for at least one organism in 8 out of 23 effluent samples. Acute toxicity for at least two organisms in 7 out of 23 effluent sampling was observed for the metal industry. The toxicity test results were assessed with chemical analyses such as COD, BOD, color and heavy metals. It was observed that the toxicity of the effluents could not be explained by using physicochemical analyses in 5 cases for metal and 4 cases for the textile industries. The results clearly showed that the use of bioassay tests produce additional information about the toxicity potential of industrial discharges and effluents.

PMID: 11878628 [PubMed - in process]

Response of the ascorbate-peroxidase of Selenastrum capricornutum to copper and lead in stormwaters.

Wong MY, Sauser KR, Chung KT, Wong TY, Liu JK.

Water Quality Control Plant, City of Palo Alto, CA 94303, USA.

The green alga Selenastrum capricornutum expresses a unique ascorbate peroxidase, that responds to copper and lead. Attempts were made to test if this peroxidase could be used to monitor the levels of copper and lead in natural waters. When S. capricornutum was exposed to a stormwater sample, the specific activity of the peroxidase in the cell extract was commensurate with the combined copper and lead contents in the sample. The peroxidase responses were also correlated with the 96 hr biomass toxicity assay of S. capricornutum. However, unlike the biomass toxicity assay, the peroxidase activity was not affected by the anions in the samples. The use of this peroxidase can be used as a marker for testing heavy metal toxicity in the water.

PMID: 11334447 [PubMed - indexed for MEDLINE]

Dredging impact on an urbanized Florida bayou: effects on benthos and algal-periphyton.

Lewis MA, Weber DE, Stanley RS, Moore JC.

US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, FL 32561-5299, USA. [email protected]

Environmental effects of dredging events have been uncommonly reported for shallow, residential estuaries characteristic of the Gulf of Mexico region. The objective of this study was to determine the impact of hydraulic dredging on an urbanized estuary. Physicochemical quality, benthic community composition, whole sediment toxicity, periphytic algal community composition and trace metal tissue quality were determined prior to and after dredging. The effects on surface water pH, dissolved oxygen, and temperature were negligible but photosynthetically active radiation was decreased at several stations. Dredging significantly reduced benthic diversity and density (P < 0.05). However, the sediments were not acutely toxic to the epibenthic, Americamysis bahia (formerly Mysidopsis bahia); survival averaged 93% (post-dredging) and to 98% (pre-dredging). There were several post-dredging taxonomic structural changes in the diatom-dominated, periphyton community but differences in mean density and three diversity indices were not significant. Trace metal concentration in periphyton after dredging were reduced from an average of 4-65% and significantly for mercury, zinc and chromium in several areas. It was concluded that the environmental impact of small-scale dredging events in urbanized near-coastal areas, based on the selected parameters, are likely to be localized and of short-term environmental consequence. The choice of the target biota, response parameters and chemical analysis are important considerations in the environmental impact assessment of these periodic episodic events.

PMID: 11706789 [PubMed - indexed for MEDLINE]

Literature review on duckweed toxicity testing.

Wang W.

Water Quality Section, Illinois State Water Survey, Peoria 61652.

Duckweed commonly refers to a group of floating, flowering plants of the family Lemnaceae. Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity. Other studies, however, indicate that duckweed plants are as sensitive to toxicity as other aquatic species. Duckweed plants are especially suitable for use in complex effluent bioassays, and for testing herbicide pollution in the aquatic environment, lake and river pollution, sediment toxicity, and the like. Duckweed and algae represent different levels of complexity in the plant kingdom. They complement each other as phytotoxicity test organisms, instead of mutually excluding each other. Many duckweed species have been studied, primarily of the Lemna and Spirodela genera. Lemna minor and L. gibba have been recommended as standard test species. Differences in duckweed test methodology occur with regard to test types, test vessels, control tests, nutrient media, end points, and applications.

Publication Types:

Review

Review, Academic

PMID: 2190824 [PubMed - indexed for MEDLINE]

Ecotoxicity of copper to aquatic biota: a review.

Nor YM.

The toxic effects of copper on numerous aquatic flora and fauna has been studied intensely over the past 10 years. In general, there is a consensus that free cupric ions are more toxic if compared with other chemical forms such as organically complexed copper. Biological indicators exhibit a tremendously wide range of sensitivity to copper with toxic effects noted at pCu as low as 10 for some algae, while aquatic macrophytes appear to have a much higher tolerance for copper (pCu less than 5.0). The sensitivity of various groups of organisms seems discrepant and anomalous with accepted standards for drinking water and industrial discharges, and recommended rates of copper sulfate application to water bodies. The toxicity of copper, however, is mitigated by the presence of naturally occurring organic compounds in waters through complexation. The regulatory function of dissolved humic matter will continue to be a vital one for as long as copper is discharged into aquatic environments.

Publication Types:

Review

PMID: 3556158 [PubMed - indexed for MEDLINE]

Cadmium-induced ultrastructural changes in Euglena cells.

Duret S, Bonaly J, Bariaud A, Vannereau A, Mestre JC.

The ultrastructure of Euglena gracilis grown in the presence of Cd showed only numerous myelin-like structures in mitochondria, chloroplasts altered in shape, and thylakoid arrangement and increase of osmiophilic plastoglobuli. These alterations indicate that respiratory processes are the initial target of Cd toxicity.

PMID: 3002782 [PubMed - indexed for MEDLINE]

Effect of Cu2+ stress on an aquatic microcosm: a holistic study.

Sugiura K, Goto M, Kurihara Y.

PMID: 6806091 [PubMed - indexed for MEDLINE]

Protective effects of certain environmental factors on the toxicity of zinc, mercury, and methylmercury to Chlorella vulgaris.

Rai LC, Gaur JP, Kumar HD.

PMID: 7274190 [PubMed - indexed for MEDLINE]

On the toxic effects of tetraethyl lead and its derivatives on the chrysophyte Poterioochromonas malhamensis. II. Triethyl lead, diethyl lead, and inorganic lead.

Roderer G.

PMID: 7274199 [PubMed - indexed for MEDLINE]

Cadmium toxicity in planktonic organisms of a freshwater food web.

Fennikoh KB, Hirshfield HI, Kneip TJ.

PMID: 98320 [PubMed - indexed for MEDLINE]

Toxicity and bioaccumulation of cadmium in Chlorella.

Hart BA, Scaife BD.

PMID: 22433 [PubMed - indexed for MEDLINE]

Use of Ulva lactuca to identify ammonia toxicity in marine and estuarine sediments.

Pelletier MC, Ho KT, Cantwell M, Kuhn-Hines A, Jayaraman S, Burgess RM.

U.S. Environmental Protection Agency, National Health and Environmental Effects Laboratory, Atlantic Ecology Division, Narragansett, Rhode Island 02882., USA. [email protected]

Toxicity identification evaluation (TIE) methods are being developed for use with whole sediments. Although a phase I TIE method has been developed to characterize ammonia toxicity in aqueous samples using the marine macroalga Ulva lactuca, the relationship between amphipod and mysid mortality and uptake by U. lactuca of bedded sediment ammonia had not been explored. Additionally, it was not known how interactions in whole sediments between metal and organic contaminants with U. lactuca and ammonia would affect TIE interpretation. The current study showed that ammonia toxicity to amphipods and mysids was reduced significantly in marine sediments in the presence of U. lactuca. The alga slightly affected metal concentrations but did not alter the concentration of organic contaminants in either overlying or interstitial waters. Conversely, ammonia uptake by U. lactuca was not affected by the presence of metal or organic contaminants in the sediments. When used with other TIE manipulations, U. lactuca can be utilized in a whole-sediment, phase I TIE to remove toxicity due to ammonia.

PMID: 11764171 [PubMed - indexed for MEDLINE]

Class III metallothioneins in response to cadmium toxicity in the marine microalga Tetraselmis suecica (Kylin) Butch.

Perez-Rama M, Herrero Lopez C, Abalde Alonso J, Torres Vaamonde E.

Departamento de Biologia Celular y Molecular, Facultad de Ciencias, Universidade da Coruna, Espana.

Microalgae are one of the most important organisms in our ecosystems being seriously affected by metal pollution. However, the microalgae Tetraselmis suecica (Kylin) Butch is tolerant to cadmium; the concentration of this metal that reduces the population growth to 50% of the control growth level is 5.8 mg/L after 96 h of exposure. In this study, class III metallothioneins were investigated for their involvement as a possible tolerance mechanism in this microalga when exposed to cadmium. A set of these molecules was purified from these microalgal cells after exposure to the metal. These polypeptides were analyzed by capillary zone electrophoresis, which is a technique that allows the length of the metallothioneins synthesized by this microalga to be known. The T. suecica cells were able to synthesize class III metallothioneins of three to six subunits of (gamma-Glu-Cys). The most abundant polypeptide possessed four subunits, and (gamma-Glu-Cys)6-Gly was the largest polypeptide synthesized by this microalga and detected by this technique. Tolerance to cadmium as a function of increasing polypeptide length is also discussed.

PMID: 11521835 [PubMed - indexed for MEDLINE]

Linking ecological impact to metal concentrations and speciation: a microcosm experiment using a salt marsh meiofaunal community.

Millward RN, Carman KR, Fleeger JW, Gambrell RP, Powell RT, Rouse MA.

Biological Sciences, Louisiana State University, Baton Rouge 70803, USA.

Microcosm experiments addressed the impact of a mixture of Cu, Cr, Cd, Pb, and Hg at three concentrations after 36 h, 12 d, and 30 d on a meiofauna-dominated salt marsh community. In addition to analyzing effects on meiofaunal abundances, the study quantified the sediment metal concentrations of all five metals and pore-water concentrations, speciation, and ligand complexation of Cu. Abundances of deposit feeders such as the polychaete Streblospio benedicti, gastropods, and bivalves were impacted at lower metal concentrations than the mainly algal-feeding copepods, ostracods, and nematodes. We suggest that this might be due to bulk ingestion of metal-contaminated sediments resulting in relatively higher metal exposure in the deposit feeders than in the other, nondeposit feeding taxa. Copepod and ostracod abundances decreased only in the highest metal treatment, where levels of inorganic Cu ([Cu']) in pore waters were similar to levels associated with both acute and subacute toxicity in published in vivo toxicity studies of marine copepods. The higher metal treatments yielded disproportionately higher pore-water [Cu] compared with sediment [Cu], suggesting saturation of sediment-associated ligands with increased additions of Cu. Similarly, the higher metal treatments appeared to reach saturation of the organic Cu ligands, with the excess pore-water [Cu] present in the more toxic, inorganic species of Cu. Acid-volatile sulfide (AVS) concentrations at sediment horizons inhabited by meiofauna were low and AVS was not considered a significant metal ligand at these depths. Since meiofauna are predominantly associated with oxic surface sediments, it is doubtful that AVS is a major factor controlling availability of free metal for exposure to these taxa.

PMID: 11521831 [PubMed - indexed for MEDLINE]

Sublethal effects of silver in zooplankton: importance of exposure pathways and implications for toxicity testing.

Hook SE, Fisher NS.

Marine Sciences Research Center, State University of New York, Stony Brook 11794-5000, USA.

In aquatic environments, organisms are exposed to contaminants via direct uptake from water and by trophic transfer. However, most toxicity tests only examine uptake via the dissolved phase. We compared the response of marine and freshwater crustacean zooplankton to silver following dissolved and food exposure. Silver, like other metals, concentrates in aquatic food chains and may exert toxicity. In standard solute exposure toxicity tests, Ag is toxic to zooplankton at concentrations of 400 nM for marine copepods and 100 nM for freshwater cladocerans, concentrations far greater than those in most waters. However, if Ag is accumulated from algal food, reproductive success decreases by >50% when algae are exposed to only 1 nM Ag in copepods and 0.5 nM Ag in cladocerans. These concentrations are within an order of magnitude of those found in contaminated estuaries. Following dietary exposure, decreased egg production and viability occur when tissue Ag concentrations increase three- to fourfold to 0.3 ppm in cladocerans and 0.5 ppm in copepods. Assimilated Ag depresses egg production by reducing yolk protein deposition and ovarian development. Our results indicate that ecologically relevant toxicity tests should consider sublethal effects of contaminants obtained from food since these effects cannot be predicted from exposures to only dissolved contaminants.

PMID: 11349858 [PubMed - indexed for MEDLINE]

Development of flow cytometry-based algal bioassays for assessing toxicity of copper in natural waters.

Franklin NM, Stauber JL, Lim RP.

Centre for Advanced Analytical Chemistry, CSIRO Energy Technology, PMB 7, Bangor, New South Wales 2234, Australia. [email protected]

Copper toxicity to the freshwater algae Selenastrum capricornutum and Chlorella sp. and the marine algae Phaeodactylum tricornutum and Dunaliella tertiolecta was investigated using different parameters measured by flow cytometry: cell division rate inhibition, chlorophyll a fluorescence, cell size (i.e., light-scattering), and enzyme activity. These parameters were assessed regarding their usefulness as alternative endpoints for acute (1-24 h) and chronic (48-72 h) toxicity tests. At copper concentrations of 10 micrograms/L or less, significant inhibition (50%) of the cell division rate was observed after 48- and 72-h exposures for Chlorella sp., S. capricornutum, and P. tricornutum. Bioassays based on increases in algal cell size were also sensitive for Chlorella sp. and P. tricornutum. Copper caused both chlorophyll a fluorescence stimulation (48-h EC50 of 10 +/- 1 micrograms Cu/L for P. tricornutum) and inhibition (48-h EC50 of 14 +/- 6 micrograms Cu/L for S. capricornutum). For acute toxicity over short exposure periods, esterase activity in S. capricornutum using fluorescein diacetate offered a rapid alternative (3-h EC50 of 90 +/- 40 micrograms Cu/L) to growth inhibition tests for monitoring copper toxicity in mine-impacted waters. For all the effect parameters measured, D. tertiolecta was tolerant to copper at concentrations up to its solubility limit in seawater. These results demonstrate that flow cytometry is a useful technique for toxicity testing with microalgae and provide additional information regarding the general mode of action of copper (II) to algal species.

PMID: 11351404 [PubMed - indexed for MEDLINE]

Interactions of chromium with microorganisms and plants.

Cervantes C, Campos-Garcia J, Devars S, Gutierrez-Corona F, Loza-Tavera H, Torres-Guzman JC, Moreno-Sanchez R.

Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana, Edificio B-3, Ciudad Universitaris, 58030 Morelia, Michoacan, Mexico. [email protected]

Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.

Publication Types:

Review

Review, Academic

PMID: 11348688 [PubMed - indexed for MEDLINE]

Interaction of toxic trace metals and mechanisms of detoxification in the planktonic diatoms Ditylum brightwellii and Thalassiosira pseudonana.

Rijstenbil JW, Sandee A, Van Drie J, Wijnholds JA.

Netherlands Institute of Ecology, Centre for Estuarine and Coastal Ecology, Yerseke, The Netherlands.

Effects of cadmium (10 nM), copper (80 nM) and zinc (150 nM) additions were studied in the marine diatom Ditylum brightwellii and the riverine diatom Thalassiosira pseudonana. Defense against oxidative stress via cellular thiol (SH) pools and superoxide dismutase (SOD) activation, detoxification via phytochelatins and cell damage were monitored in metal-exposed exponential-phase cells and controls, grown in estuarine medium. Total SH and reduced+oxidized glutathione (GSH+GSSG) in T. pseudonana were much higher than in D. brightwellii. In T. pseudonana, total SH and GSH decreased at 322 nM Zn, and GSH increased at 80 nM Cu but decreased at 119 nM Cu. GSH:GSSG ratios were low, while phytochelatins were not detectable in metal-exposed D. brightwellii. Cd-exposed T. pseudonana made more phytochelatins than Cu-exposed cells, and in different proportions. At 322 nM Zn, SOD activity decreased in T. pseudonana. Zn caused a major, and Cu a minor increase of SOD activity in D. brightwellii; inhibition of photosynthesis was observed in Cu-exposed D. brightwellii, probably due to oxidative damage. The C:N ratios were higher and protein contents lower in Cu-exposed cells of both species, which might indicate excretion due to a loss of cell membrane integrity. From these results, it is hypothesized that T. pseudonana has evolved an effective detoxification mechanism as a result of a more severe exposure to toxic metals in rivers and estuaries. In contrast, D. brightwellii, a marine-estuarine species, cannot adjust well to metal exposure. Its poor defense against metal toxicity was marked by low SH-contents.

PMID: 7917426 [PubMed - indexed for MEDLINE]

Influence of selenium on toxicity of some heavy metals in the green alga Scenedesmus obliquus.

Issa AA, Adam MS.

Botany Department, Faculty of Science, Assiut University, Egypt.

The green alga Scenedesmus obliquus was incubated with heavy metals (Cd2+, Zn2+, Mn2+, Ni2+) with and without selenium. S. obliquus exhibited higher rates of growth and some metabolic activities in cultures containing 0.1 mmol/L Se than those only containing the heavy metals. The positive effect of Se was found with all metals but was negligible with Mn2+.

PMID: 10983237 [PubMed - indexed for MEDLINE]

Study on the toxicity of sodium bromide to different freshwater organisms.

Canton JH, Wester PW, Mathijssen-Spiekman EA.

The toxicity of sodium bromide for freshwater organisms was tested using algae (Scenedesmus pannonicus), crustaceans (Daphnia magna) and fish (Poecilia reticulata and Oryzias latipes). Depending on the species tested, the acute toxicity varied from 44 to 5800 mg Br-/litre (EC50 values) and the No Observed Effect Concentrations (NOEC values) in the long-term tests varied from 7.8 to 250 mg Br-/litre. Bromide ion markedly impaired reproduction in both crustaceans and fish. Histologically no effects were observed in the long-term test with Oryzias, but in the reproduction test with Poecilia, hyperplasia of the thyroid, atrophy and degeneration of the musculature and regressive changes in the female reproductive tract were observed. As a criterion of water quality, 1 mg Br-/litre has been proposed, on the basis of reproductive performance in the Poecilia test. The concentrations found in surface water frequently exceed this value and sometimes reach levels at which acute effects on water organisms can be expected.

PMID: 6684619 [PubMed - indexed for MEDLINE]

Depletion of cellular iron by bps and ascorbate: effect on toxicity of adriamycin.

Nyayapati S, Afshan G, Lornitzo F, Byrnes RW, Petering DH.

Department of Chemistry, University of Wisconsin, Milwaukee 53201, USA.

A new method was developed that reduces the intracellular iron content of cells grown in serum-containing culture without involving the significant uptake of iron-chelating agents into cells. Negatively charged bathophenanthrolinedisulfonate (BPS), together with ascorbate, caused cells to lose much of their cellular iron without causing much depression in HL-60 or H9c2 (2-1) cell proliferation over a 48-h period. When added to serum supplemented RPMI-1640 culture media, BPS and ascorbate efficiently reduced and competed for iron in Fe(III) transferrin to form Fe(II)(BPS)3. The reaction also occurred with purified human iron-transferrin. When cells were incubated with growth medium containing serum that had been treated with BPS and ascorbate for 24 h, little or no BPS2- or Fe(II)(BPS)(4-)3 entered the cells, according to direct measurements and in agreement with the highly unfavorable 1-octanol/water partition coefficients for these molecules. However, iron was mobilized out of both cell types. After 24 h incubation of cells in this medium, there was no change in the activities of catalase and superoxide dismutase, or in the concentration of glutathione. Glutathione peroxidase was elevated 9%. Using HL-60 and H9c2 (2-1) cells made iron deficient with BPS and ascorbate, HL-60 cells grown in defined-growth media in the absence of iron-pyridoxal isonicotinoyl hydrazone, or Euglena gracilis cells maintained in a defined medium that was rigorously depleted of iron, it was shown that the cytotoxicity of adriamycin is markedly dependent on the presence of iron in each type of cell. Similar results were obtained when HL-60 cells were grown in RPMI-1640 culture medium and serum that had been incubated for 24 h in BPS and ascorbate and then chromatographed over a Bio-Rad desalting column to remove small molecules including BPS, ascorbate, and Fe(II)(BPS)3.

PMID: 8720902 [PubMed - indexed for MEDLINE]

A mimic of superoxide dismutase activity protects Chlorella sorokiniana against the toxicity of sulfite.

Rabinowitch HD, Rosen GM, Fridovich I.

Department of Field and Vegetables, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel.

The spin-trapping agent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) has been used to demonstrate the light-dependent production of O2- by Chlorella sorokiniana. In the presence of SO3= a light-dependent production of the sulfur trioxy anion radical (SO3-.) could also be seen. A complex prepared by reacting desferrioxamine with MnO2, which catalyzes the dismutation of O2-, protected the alga against the toxicity of sulfite. The data suggest that SO2 toxicity is at least partially due to the effects of sulfoxy-free radicals generated by the oxidation of SO3= by O2-.

PMID: 2536342 [PubMed - indexed for MEDLINE]

[Toxic effects of Cu, Zn and Mn on the inhibition of Chlorella pyrenoidosa's growth]

[Article in Chinese]

Yan H, Wang X, Lin Y, Wen G.

State Key Lab. of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

A standard method of algal bioassay for evaluating the toxicity of toxic chemicals was applied in the study. It was found that safety concentrations of Cu, Zn and Mn for Chlorella pyrenoidosa's growth were 31.8 micrograms/L, 65.0 micrograms/L and 5.5 mg/L, and 96 h-EC50 were 67.3 micrograms/L, 473.0 micrograms/L and 17.0 mg/L, respectively. According to both safety concentration and 96 h-EC50, the toxic sequences of these metals from high to low on the inhibition of C. pyrenoidosa's growth were Cu, Zn and Mn. The different affinities between different metal ions and algal cells are mainly responsible for the different inhibitions of C. pyrenoidosa's growth.

PMID: 11382036 [PubMed - indexed for MEDLINE]

Domoic acid-induced neurodegeneration resulting in memory loss is mediated by Ca2+ overload and inhibition of Ca2+ + calmodulin-stimulated adenylate cyclase in rat brain (review).

Nijjar MS, Nijjar SS.

Department of Anatomy and Physiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown C1A 4P3, PEI, Canada. [email protected]

Domoic acid is a shellfish toxin which produces neurodegeneration and CNS dysfunction, notably a loss of short-term memory. This toxin was found in blue mussels (Mytilus edulis) cultivated in river water in the east coast of Prince Edward Island in Canada and caused human poisoning. The toxin was localized in the stomach of blue mussels, which was engorged with algae, Nitzschia pungens, that were filtered from the surrounding water. The toxin was isolated from contaminated mussels or phytoplankton, and identified chemically as domoic acid (DOM) which is a tricarboxylic amino acid. Due to its structural resemblance to glutamic, aspartic and kainic acids, DOM was considered to produce excitotoxicity by similar mechanism(s). However, the latest evidence indicates differences in its mode of action from these excitatory agonists. We propose that DOM induces toxicity via changes in intracellular concentration of Ca2+ ([Ca2+]i). Results of our studies demonstrate that DOM elevated [Ca2+]i in brain slices. Glucose deprivation and removal of Na+ from the Krebs-bicarbonate medium further elevated [Ca2+]i, suggesting a relationship between glucose metabolism (cell energy), Na+ and Ca2+ transfer across neuronal membrane. DOM-induced rise in [Ca2+]i was due to enhanced Ca2+ influx and its mobilization from the endoplasmic reticulum. In addition, diminished Ca2+-ATPase activity due to lack of ATP, and variable amounts and expression of calcium binding proteins (CaBP) appear to contribute to an elevation in [Ca2+]i in response to DOM. Most interestingly, DOM inhibited Ca2+ and calmodulin-stimulated adenylate cyclase activity in brain membranes, resulting in reduced level of cyclic AMP. Cyclic AMP is known to activate protein kinase A to enhance phosphorylation of Ca2+ channels, thereby, reducing Ca2+ influx to prevent the development of Ca2+ overload which is detrimental to neuronal cell function (neuroprotection). However, DOM reduced cyclic AMP level, diminishing the feedback control of cyclic AMP on Ca2+ influx via Ca2+ channels, thereby, allowing continuing enhanced Ca2+ influx, resulting in Ca2+ overload which adversely affects many intracellular processes to induce toxicity. Ca2+ and CaM-stimulated adenylate cyclase activity in brain is highly correlated with the acquisition and retention of memory in different organisms. Calcium binding proteins bind Ca2+ reversibly and provide intracellular Ca2+ buffering, thereby, protecting neuronal cell from damage by Ca2+ overload in response to DOM. DOM appears to interfere with the cross talk between Ca2+ and cyclic AMP which is necessary for neuronal cell function. We have also demonstrated that DOM stimulates GLU release from synaptosomes and may produce some of its toxic effects via excess GLU in the neuronal synapse. In conclusion, DOM-induced neurodegeneration resulting in a loss of memory is mediated by Ca2+ overload, inhibition of Ca2+ and CaM-stimulated adenylate cyclase activity, and/or by the enhanced GLU release in rat brain.

Publication Types:

Review

Review, Tutorial

PMID: 10998428 [PubMed - indexed for MEDLINE]

[Physical and chemical properties of vanadium and its compounds]

[Article in Spanish]

Tudares C.

Gerencia de Ecologia Humana, Instituto para el Control y la Conservacion de la Cuenca del Lago de Maracaibo (ICLAM), Venezuela.

Vanadium is present in the earth crust mainly in the heavy oils, carbons and bituminous materials, where is associated with the heavy fractions. Many live beings have vanadium in their tissues. Their industrial applications are fundamentally based in the physical and chemical properties. From the environmental point of view the vanadium emissions to the atmosphere are produced in areas around siderurgical industries, oil refineries and cities that use fossil fuels for heating. The pollution process in these areas is associated partially with the presence of vanadium compounds, as is the case in the eastern coast of the lake of Maracaibo, Venezuela. Some clinical-epidemiological researches report a high incidence of congenital malformations at the Central Nervous System level, and this has been associated with the intense oil activities of the region. The high incidence of the Central Nervous System congenital malformations could be associated with the vanadium compounds present in the eastern coast of the lake of Maracaibo; here is the interest in the physical and chemical properties knowledge of vanadium and their compounds.

PMID: 9650456 [PubMed - indexed for MEDLINE]

The toxicity of brass dust to the microalgae Ankistrodesmus falcatus and Selenastrum capricornutum.

Haley MV, Johnson DW, Hart GS, Muse WT, Landis WG.

The toxicity of brass dust was examined by conducting 96 h growth inhibition tests. Two species of algae were used, Ankistrodesmus falcatus (EC50 = 0.316 mg brass/l) and Selenastrum capricornutum (EC50 = 0.056 mg brass/l). Brass dissociates into two components, Cu (68.5%) and Zn (27.5%). Enhanced algal growth was exhibited at concentrations of 0.01 and 0.001 mg brass/l. Available literature on the toxicity of copper to S. capricornutum (EC50 = 0.047 mg Cu/l), indicate that the toxicity of brass dust is due to the ionized copper. Reported toxicities of zinc are orders of magnitude lower than copper. The ionization of the brass is dependent on pH and hardness. The literature cites cases in which copper toxicity varies with pH, clay content and dissolved organics. At present little is known of the fate and distribution of brass dust upon the release into the environment. However, the presence of heavy metals has consistently been shown to impact aquatic systems.

PMID: 3760454 [PubMed - indexed for MEDLINE]

Effects of photocatalytic reactions on marine plankton: titanium dioxide powder as catalyst on the body surface.

Matsuo S, Anraku Y, Yamada S, Honjo T, Matsuo T, Wakita H.

Department of Chemistry, Faculty of Science, Fukuoka University, Japan.

Photocatalytic effects of TiO2 powder on marine plankton were examined by the use of either brine shrimp Artemia salina or noxious red tide flagellate Chattonella antiqua as a probe. After UV (365 nm) irradiation for ca. 1 hour, A. salina stopped moving and the body surface was completely covered by TiO2 powder. Similar photoirradiation of C. antiqua, on the other hand, induced deformation of the body from spindle to round shape within 20 minutes. The deformed C. antiqua recovered to normal shapes, when the cells were kept in the same conditions but without UV irradiation for more than 40 minutes. On the prolonged UV irradiation (more than 100 minutes), however, the cells burst and came to annihilation. The photocatalytic reactions of TiO2 on the body surface are thus concluded to induce fatal damages to these microorganisms.

PMID: 11545364 [PubMed - indexed for MEDLINE]

Caesium accumulation by microorganisms: uptake mechanisms, cation competition, compartmentalization and toxicity.

Avery SV.

School of Pure and Applied Biology, University of Wales College of Cardiff, UK.

The continued release of caesium radioisotopes into the environment has led to a resurgence of interest in microbe-Cs interactions. Caesium exists almost exclusively as the monovalent cation Cs+ in the natural environment. Although Cs+ is a weak Lewis acid that exhibits a low tendency to form complexes with ligands, its chemical similarity to the biologically essential alkali cation K+ facilitates high levels of metabolism-dependent intracellular accumulation. Microbial Cs+ (K+) uptake is generally mediated by monovalent cation transport systems located on the plasma membrane. These differ widely in specificity for alkali cations and consequently microorganisms display large differences in their ability to accumulate Cs+; Cs+ appears to have an equal or greater affinity than K+ for transport in certain microorganisms. Microbial Cs+ accumulation is markedly influenced by the presence of external cations, e.g. K+, Na+, NH4+ and H+, and is generally accompanied by an approximate stoichiometric exchange for intracellular K+. However, stimulation of growth of K(+)-starved microbial cultures by Cs+ is limited and it has been proposed that it is not the presence of Cs+ in cells that is growth inhibitory but rather the resulting loss of K+. Increased microbial tolerance to Cs+ may result from sequestration of Cs+ in vacuoles or changes in the activity and/or specificity of transport systems mediating Cs+ uptake. The precise intracellular target(s) for Cs(+)-induced toxicity has yet to be clearly defined, although certain internal structures, e.g. ribosomes, become unstable in the presence of Cs+ and Cs+ is known to substitute poorly for K+ in the activation of many K(+)-requiring enzymes.

Publication Types:

Review

Review, Tutorial

PMID: 7766213 [PubMed - indexed for MEDLINE]

Response of Selenastrum capricornutum to zinc sulfides.

Hendricks AC.

PMID: 621827 [PubMed - indexed for MEDLINE]

A screening technique for estimating copper toxicity to estuarine phytoplankton.

Erickson SJ, Lackie N, Maloney TE.

PMID: 5458417 [PubMed - indexed for MEDLINE]

Microbial transformation of mercury species and their importance in the biogeochemical cycle of mercury.

Baldi F.

Department of Environmental Biology, University of Siena, Italy.

Publication Types:

Review

Review, Tutorial

PMID: 9046572 [PubMed - indexed for MEDLINE]

Flow cytometry determination of acute physiological changes in a marine diatom stressed by copper.

Cid A, Fidalgo P, Herrero C, Abalde J.

Departamento de Biologia Celular y Molecular, Facultad de Ciencias, Universidad de La Coruna, Espana.

Flow cytometry (FCM) was used to determine changes in cellular volume, transmembrane potential, mitochondrial membrane potential and intracellular pH in the marine microalga Phaeodactylum tricornutum immediately (5 to 10 seconds) after the addition of selected concentrations of copper. An acute increase in the forward scatter signal of this diatom was detected after the addition of 10 mg 1-1 of copper. Stress produced by the copper addition resulted in various physiological alterations that can be easily and quickly detected by FCM: (i) the hyperpolarization of the cell membrane, as a result of an immediate increase in the cytoplasmic membrane potential, (ii) the increase of the mitochondrial membrane potential, being maximum at the higher copper concentration assayed, and (iii) the increase in the intracellular pH with the highest copper concentration assayed (10 mg 1-1).

PMID: 8588841 [PubMed - indexed for MEDLINE]

Different responses of the marine diatom Phaeodactylum tricornutum to copper toxicity.

Reiriz S, Cid A, Torres E, Abalde J, Herrero C.

Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de La Coruna.

Different responses of the marine diatom Phaeodactylum tricornutum (Bohlin) to toxic copper concentrations were investigated. Besides the classical variables applied to toxicity studies in microalgae, such as growth or chlorophyll a content, other variables analyzed by flow cytometry were used. Toxic effects due to copper concentration were observed. Cell density reached in the stationary phase was reduced to 50% in cultures with 20 mg Cu/l, with respect to control cultures without copper. Cell light scatter properties (related to cell volume and intracellular granularity) and chlorophyll a fluorescence of microalgal cells were determined by flow cytometry analysis at the beginning of growth, 1 h after copper exposure, and when cultures reached the stationary phase (72 h). After 1 h of exposure to metal, no differences were observed, but when cultures reached the stationary phase, a gradual increase in the variables analyzed by flow cytometry was observed as the copper concentration increased. The increase in chlorophyll a fluorescence detected by flow cytometry was not correlated with an increase in the cell content of this photopigment, thus indicating an inhibitory effect of copper on photosystem II.

PMID: 7873102 [PubMed - indexed for MEDLINE]

Toxic effects of cobalt and zinc to Chlorella pyrenoidosa (26) in soft and hard water.

Wong MH.

Different concentrations (0.83, 3.33, 10 ppm) of cobalt (cobalt sulphate) and zinc (zinc chloride) were added to bristol media prepared using soft water (addition of 20 mg/l calcium carbonate) and hard water (addition of 400 mg/l calcium carbonate). A known amount of Chlorella pyrenoidosa (26) was inoculated into various media, and the number of Chlorella cells was counted every other day for a period of 8 days. Cobalt and zinc were more toxic in media prepared using soft water than hard water as revealed by the growth rate of C. pyrenoidosa. These results agree with studies elsewhere on other aquatic organisms.

PMID: 7453572 [PubMed - indexed for MEDLINE]

[Study on the toxicity of copper complexes for Scenedesmus quadricauda Breb]

[Article in Russian]

Khobot'ev VG, Kankov VI, Rukhadze EG.

PMID: 5396589 [PubMed - indexed for MEDLINE]

Toxicity of mercury to phytoplankton.

Nuzzi R.

PMID: 4555438 [PubMed - indexed for MEDLINE]

[Use of microalgae for nutritional purposes]

[Article in German]

Soeder CJ.

Mass cultures of planktonic microalgae can render large quantities of proteinaceous matter. The good nutritional quality of microalgal protein has been proven both for animals and for human. The toxicologic safety of microalgal biomasses is, however, not yet sufficiently established. This requires further toxicologic studies, before cultivated mocralgae can commercially be utilized as ingredients of animal feed, or as food additives. Both types of nutritional application may become economically feasible.

PMID: 934345 [PubMed - indexed for MEDLINE]

[Use of a standard algae test for the study of toxicity phenomena]

[Article in Italian]

Chiaudani G, Vighi M.

PMID: 693327 [PubMed - indexed for MEDLINE]

Sulfophthalocyanines for photodynamic inactivation of viruses in blood products: effect of structural modifications.

Allen CM, Weber JM, van Lier JE.

MRC Group in the Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.

Transmission of infectious disease through blood transfusions is well known. Ultraviolet irradiation, solvents, and detergents provide a means of sterilizing noncellular blood components. However, these harsh methods are not applicable to cellular blood products. Recently, attempts have been made to sterilize biological fluids using photodynamic treatment and phthalocyanine (Pc) dyes have been advanced as photosensitizers for this purpose. We have evaluated a series of water-soluble Pc, chelated with different central metal ions, substituted to different degrees with sulfonato and t-butyl groups, for their effectiveness to reduce virus infectivity in red blood cell suspensions. Vaccinia virus cytopathogenicity was determined by endpoint serial dilutions in the CV-1 cell line. Anti-viral activity increased with the central metal ion in the following: Ga(III) < Al(III) < Zn(II), and varied inversely with the degree of sulfonation. Furthermore, addition of a t-butyl group onto the trisulfonated dyes (PcS3[t-Bu]) resulted in a 5-40-fold increase in anti-viral potency, suggesting that amphiphilicity enhances the photodynamic activity of the dye. Strong anti-viral photosensitizing properties cannot be the sole selection criterion. Of equal importance is the preservation of blood component integrity. Accordingly, the photohemolytic activity of the dyes was evaluated using the rate of hemolysis as a parameter and a toxicity index was defined. Among the most active dyes, the AlPcS3(t-Bu) complex exhibited the most favorable anti-viral properties combined with a low toxicity index. Our results suggest that trisulfophthalocyanines, bearing an additional t-butyl group to enhance amphiphilicity, are particularly promising dyes for photodynamic blood sterilization.

PMID: 7638264 [PubMed - indexed for MEDLINE]

Direct measurement of aluminum uptake and distribution in single cells of Chara corallina.

Taylor GJ, McDonald-Stephens JL, Hunter DB, Bertsch PM, Elmore D, Rengel Z, Reid RJ.

Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9.

Quantitative information on the uptake and distribution of Al at the cellular level is required to understand mechanisms of Al toxicity, but direct measurement of uptake across the plasma membrane has remained elusive. We measured rates of Al transport across membranes in single cells of Chara corallina using the rare (26)Al isotope, an emerging technology (accelerator mass spectrometry), and a surgical technique for isolating subcellular compartments. Accumulation of Al in the cell wall dominated total uptake (71-318 microgram m(-2) min(-1)), although transport across the plasma membrane was detectable (71-540 ng m(-2) min(-1)) within 30 min of exposure. Transport across the tonoplast was initially negligible, but accelerated to rates approximating uptake across the plasma membrane. The avacuolate protoplasm showed signs of saturation after 60 min, but continued movement across the plasma membrane was supported by sequestration in the vacuole. Saturation of all compartments was observed after 12 to 24 h. Accumulation of Al in the cell wall reflected variation in inverted question markAl(3+) inverted question mark induced by changes in Al supply or complexing ligands, but was unaffected by pH. In contrast, transport across the plasma membrane peaked at pH 4.3 and increased when inverted question markAl(3+) inverted question mark was reduced by complexing ligands. Cold temperature (4 degrees C) reduced accumulation in the cell wall and protoplasm, whereas 2,4-dinitrophenol and m-chlorocarbonylcyanidephenyl hydrazone increased membrane transport by 12- to 13-fold. Our data suggest that the cell wall is the major site of Al accumulation. Nonetheless, membrane transport occurs within minutes of exposure and is supported by subsequent sequestration in the vacuole. The rapid delivery of Al to the protoplasm suggests that intracellular lesions may be possible.

PMID: 10889247 [PubMed - indexed for MEDLINE]

Characteristics of non-specific permeability and H+-ATPase inhibition induced in the plasma membrane of Nitella flexilis by excessive Cu2+.

Demidchik V, Sokolik A, Yurin V.

Department of Physiology and Biochemistry of Plants, Biological Faculty, Belarus State University, Minsk. [email protected]

Effects of Cu2+ on a non-specific conductance and H+-ATPase activity in the plasma membrane of the freshwater alga Nitella flexilis L. Agardh was studied using a conventional microelectrode voltage-clamp technique. We show that a Cu2+-induced increase in the non-specific conductance is related to the formation of pores in the plasma membrane. Pore formation is the result of unidentified chemical reactions, since the Q10 for the rate of increase of conductance over time was about 3. Various oxidants and antioxidants (10 mmol/l H2O2, 10 mmol/l ascorbate, 100 microg/ml superoxide dismutase, and 100 microg/ml catalase) did not alter Cu2+-induced changes in the plasma membrane conductance, suggesting that the effect of Cu2+ was unrelated to peroxidation of plasma-membrane lipids. In contrast, organic and inorganic Ca2+-channel antagonists (nifedipine, Zn2+, Cd2+, Fe2+, Ni2+) inhibited the Cu2+-induced non-specific conductance increase. This suggests that changes in Ca2+ influx underlie this effect of Cu2+. Decreasing the pH or the ionic strength of external solutions also inhibited the Cu2+-induced plasma-membrane conductance increase. Copper was also found to inhibit plasma-membrane H+-ATPase activity with half-maximal inhibition occurring at about 5-20 micromol/l and full inhibition at about 100-300 micromol/l. The Hill coefficient of Cu2+ inhibition of the H+-ATPase was close to two.

PMID: 11525515 [PubMed - indexed for MEDLINE]

The effects of heavy metals (other than mercury) on marine and estuarine organisms.

Bryan GW.

PMID: 4396393 [PubMed - indexed for MEDLINE]

Environmental hazards of aluminum to plants, invertebrates, fish, and wildlife.

Sparling DW, Lowe TP.

National Biological Service, Patuxent Environmental Science Center, Laurel, MD 20708, USA.

Aluminum is extremely common throughout the world and is innocuous under circumneutral or alkaline conditions. However, in acidic environments, it can be a major limiting factor to many plants and aquatic organisms. The greatest concern for toxicity in North America occurs in areas that are affected by wet and dry acid deposition, such as eastern Canada and the northeastern U.S. Acid mine drainage, logging, and water treatment plant effluents containing alum can be other major sources of Al. In solution, the metal can combine with several different agents to affect toxicity. In general, Al hydroxides and monomeric Al are the most toxic forms. Dissolved organic carbons, F, PO(3)3- and SO(4)2- ameliorate toxicity by reducing bioavailability. Elevated metal levels in water and soil can cause serious problems for some plants. Algae tend to be both acid- and Al tolerant and, although some species may disappear with reduced pH, overall algae productivity and biomass are seldom affected if pH is above 3.0. Aluminum and acid toxicity tend to be additive to some algae when pH is less than 4.5. Because the metal binds with inorganic P, it may reduce P availability and reduce productivity. Forest die-backs in North America involving red spruce, Fraser fir, balsam fir, loblolly pine, slash pine, and sugar maples have been ascribed to Al toxicity, and extensive areas of European forests have died because of the combination of high soil Al and low pH. Extensive research on crops has produced Al-resistant cultivars and considerable knowledge about mechanisms of and defenses against toxicity. Very low Al levels may benefit some plants, although the metal is not recognized as an essential nutrient. Hyperaccumulator species of plants may concentrate Al to levels that are toxic to herbivores. Toxicity in aquatic invertebrates is also acid dependent. Taxa such as Ephemeroptera, Plecoptera, and Cladocera are sensitive and may perish when Al is less than 1 mg.L-1 whereas dipterans, molluscs, and isopods seem to be tolerant. In Al-sensitive species, elevated levels (approximately 500 micrograms.L-1) affect ion regulation and respiratory efficiency. Toxicity tends to be greatest near a species' threshold of pH sensitivity. At lower pHs, Al may have a slight ameliorative effect by interfering with H+ transport across membranes. Aquatic invertebrates can accumulate very high levels of Al, but most of this appears to be through adsorption rather than assimilation. Aluminum concentrations may be as high as 5000 mg.kg-1 in insects and greater than 17,000 mg.kg-1 in other invertebrates.(ABSTRACT TRUNCATED AT 400 WORDS)

Publication Types:

Review

Review, Academic

PMID: 7494908 [PubMed - indexed for MEDLINE]

Environmental cadmium in Europe.

Jensen A, Bro-Rasmussen F.

FORCE Institutes, Division for Isotope Techniques and Analysis, Brondby, Denmark.

The present article reviews information from the latest 10 years concerning fate and exposure of cadmium in the environment, on ecotoxicological effects, and on critical pathways leading to human and environmental exposure. It emphasizes the situation within the Community of European Countries by referring to limit values used in the EEC and some of its member states for emissions to water, air and soil. Estimates have been made on total emission balances for the Netherlands, Denmark, and for the EEC as a whole. The balances show that 70-90% of all cadmium circulating in the Community is disposed of as waste in solid waste deposits. Production and use patterns are presently changing, as indicated by reduced consumption in recent years of cadmium for plating, stabilizers and pigments in several countries as a result of regulations. However, significant increases in consumption for cadmium-containing batteries have occurred, resulting globally in increasing trends for the total consumption and production. Cadmium in sediments is more mobile than described earlier. Aquatic organisms can be classified in order of decreasing accumulation: algae greater than molluscs greater than crustaceans greater than fish. There is no evidence of biomagnification of cadmium within marine or fresh water food webs. Cadmium may enter into plants via roots or by foliar adsorption following atmospheric deposition. Biomagnification in terrestrial food chains is not observed. The uptake into plants is plant specific. Within plants significant variations are seen with concentrations generally decreasing in the order: roots greater than leaves greater than fruiting parts greater than seeds. A compilation of cadmium in air, in the aquatic environment and in soil is given. A downward trend during the 1970s to mid-1980s seems to be evidenced from various Northern European studies on cadmium air concentrations as well as for deposition rates of cadmium. In rivers, the dissolved cadmium concentrations are generally found to be relatively low (10-500 ng/L). In seawater, cadmium concentrations are found at 0.5-10 ng/L in oceanic or open marine areas, while elevated concentrations are reported in more closed marine areas and especially in coastal zones close to polluted estuaries. In fresh water, lake sediments concentrations 3-30 times higher than the background concentrations are reported in the surface layers of sediments. A significant decrease in such pollution has been observed within the recent 10 years. For marine sediments, enrichment factors of two are found in sediments from open areas and locally even 5-10 times.(ABSTRACT TRUNCATED AT 400 WORDS)

Publication Types:

Review

Review, Academic

PMID: 1509176 [PubMed - indexed for MEDLINE]

[Effect of carbaryl and lead on phenols, chlorophyll and proteins of the microalga Ankistrodesmus falcatus]

[Article in Spanish]

Martinez-Tabche L, German-Faz C, Ramirez-Mora B, Galar-Castelan I.

Laboratorio de Toxicologia Acuatica, Departamento de Toxicologia de Graduados, Escuela Nacional de Ciencias Biologicas, I.P.N., Mexico, D.F., Mexico.

Considering that Ankistrodesmus falcatus is very sensitive to different pollutants, in this work the effect of lead, carbaryl and a mixture of both pollutants on protein, chlorophyll and phenols concentration in this microalga have been studied. At different lots of Ankistrodesmus falcatus in the middle of the log growth phase, different concentrations of lead, carbaryl and a mixture of both pollutants were added, during 24, 48 and 72 h. Chlorophyll, proteins and phenols concentration was measured. The results show that the mixture of lead-carbaryl produces a major toxic effect than the xenobiotics by themselves, so it has been suggested that to establish permissible limits it is necessary to consider the synergism presented in simultaneous exposure to both xenobiotics. It is suggested to use phenols determination as a primary indicator of environmental impact in an aquatic ecosystem.

PMID: 8552881 [PubMed - indexed for MEDLINE]

Runoff rates and ecotoxicity of zinc induced by atmospheric corrosion.

Karlen C, Wallinde IO, Heijerick D, Leygraf C, Janssen CR.

Division of Corrosion Science, Royal Institute of Technology, Stockholm, Sweden.

Initiated by regulatory restrictions on the use of zinc for various building and construction applications, together with a lack of knowledge related to the release of zinc induced by atmospheric corrosion, a major interdisciplinary research project was implemented to generate data to be used in future risk assessment. Runoff rates from a large number of commercially available zinc-based materials have been determined on panels inclined 45 degrees from the horizon, facing south, during a 1-year atmospheric exposure in an urban environment in Sweden. Possible environmental effects of runoff water immediately after leaving the surface of the various materials have been evaluated during two different sampling periods of varying season and zinc concentration, using the standard growth inhibition test with algae. Raphidocelis subcapitata (formerly Selenastrum capricornutum). Zinc-specific biosensors with the bacterial strain of Alcaligenes eutrophus, and computer modeling using the water-ligand model MINTEQA2 and the humic aquatic model WHAM, have been used to assess the bioavailability and chemical speciation of zinc in the runoff water. An excellent consistency between the different methods was observed. The results show considerably lower runoff rates of zinc (0.07-3.5 g m(-2) year(-1)) than previously being used for regulatory restrictions, and the concentration of zinc to be predominantly responsible for the observed toxicity of the runoff water towards the green algae. The majority of the released zinc quantity was found to be present as free hydrated zinc ions and, hence, bioavailable. The data do not consider changes in bioavailability and chemical speciation or dilution effects during entry into the environment, and should therefore only be used as an initial assessment of the potential environmental effect of zinc runoff from building applications. This interdisciplinary approach has the potential for studies on the environmental fate of zinc in soil or aquatic systems.

PMID: 11589397 [PubMed - indexed for MEDLINE]

Toxicity assessment of total dissolved solids in effluent of Alaskan mines using 22-h chronic Microtox and Selenastrum capricornutum assays.

LeBlond JB, Duffy LK.

Institute of Arctic Biology and the Department of Chemistry and Biochemistry, University of Alaska Fairbanks, 99775, USA.

In order to overcome limitations associated with the Daphnia assay, we have explored two alternative assays, the 22-h chronic Microtox test and the 3-day S. capricornutum test, as substitutes. During this study, we compared the two assays using both a simple TDS standard solution and field water samples from two Alaskan mines. Using EC20 values, our results suggest that simple TDS standard solutions are not representative of environmental water samples of equivalent TDS concentrations. When comparing assays, our results showed that the 22-h Microtox assay was more reproducible and sensitive to effluent waters than the algal assay. Principle component analysis indicated that the 22-h Microtox test was generally more sensitive to nickel, ammonia and chloride while the S. capricornutum growth test appeared sensitive to cadmium levels.

Publication Types:

Evaluation Studies

PMID: 11346040 [PubMed - indexed for MEDLINE]

Potential use of flow cytometry in toxicity studies with microalgae.

Franqueira D, Orosa M, Torres E, Herrero C, Cid A.

Laboratorio de Microbioloxia, Facultade de Ciencias, Universidade da Coruna, Spain.

Cytotoxic effects of aquatic pollutants on microalgae are very heterogeneous, and they are influenced by environmental conditions and the test species. Stress produced by copper or paraquat addition to the culture medium of two microalgae was analysed by flow cytometry. Parameters assayed were: cell volume, chlorophyll a fluorescence and cell viability. The variety of results obtained in the present study reveals that flow cytometry is a useful tool in the toxicity tests with microalgae, both marine and freshwater species, and for different kind of pollutants.

PMID: 10803540 [PubMed - indexed for MEDLINE]

Toxicity of nickel ores to marine organisms.

Florence TM, Stauber JL, Ahsanullah M.

Centre for Environmental and Health Science, Oyster Bay, NSW, Australia.

Queensland Nickel proposes to import New Caledonian (Ballande) and Indonesian (Gebe) nickel ores, one option being ship-to-barge transfer in Halifax Bay, North Queensland. Because small amounts of ore may be split during the unloading and transfer operations, it was important to investigate the potential impact of the spilt ore on the ecological health of the Bay. Long-term leaching of the ores with seawater showed that only nickel and chromium (VI) were released from the ores in sufficient concentrations to cause toxicity to a range of marine organisms. The soluble fractions of nickel and chromium (VI) were released from the ores within a few days. Nickel, chromium (VI) and the ore leachates showed similar toxicity to the juvenile banana prawn Penaeus merguiensis, the amphipod Allorchestes compressa and both temperature (22 degrees C) and tropical (27 degrees C) strains of the unicellular marine alga Nitzschia closterium. In a series of 30-day sub-chronic microcosm experiments, juvenile leader prawns Penaeus monodon, polychaete worms Galeolaria caespitosa and the tropical gastropod Nerita chamaeleon were all very resistant to the nickel ores, with mortality unaffected by 700 g ore per 50 l seawater. The growth rate of the leader prawns was, however, lower than that of the controls. From these data, a conservative maximum safe concentration of the nickel ores in seawater is 0.1 g l-1. The nickel ore was not highly toxic and if spilt in the quantities predicted, would not have a significant impact on the ecological health of the Bay.

PMID: 8029690 [PubMed - indexed for MEDLINE]

Effects of cadmium on a microbial food chain, Chlamydomonas reinhardii and Tetrahymena vorax.

Lawrence SG, Holoka MH, Hamilton RD.

Department of Fisheries and Oceans, Central and Arctic Region, Freshwater Institute Science Laboratory, Winnipeg, Manitoba, Canada.

A steady-state microbial food chain consisting of the green alga Chlamydomonas reinhardii and the ciliated protozoan Tetrahymena vorax was established in a two-stage, nitrogen-limited chemostat. The lowest concentration of cadmium which produced a toxic effect at the population level was between 7.5 and 10 micrograms l-1. The algal population acclimated to the presence of cadmium up to 40 micrograms l-1 added in increments over time, but demonstrated lowered cell numbers and reduced cell weights. Protozoan populations acclimated to 40 micrograms Cd l-1 added incrementally if the rate of dilution was lowered. Abrupt elevation of the cadmium concentration to 40 micrograms l-1 resulted in extreme fluctuations in the specific growth rates of both populations and the incipient loss of all cells from the system (washout).

PMID: 2609152 [PubMed - indexed for MEDLINE]

Drugs from the sea.

Ruggieri GD.

PMID: 9691 [PubMed - indexed for MEDLINE]

Changes in epilithic communities due to individual and combined treatments of zinc and snail grazing in stream mesocosms.

Genter RB, Colwell FS, Pratt JR, Cherry DS, Cairns J Jr.

Department of Biology, Virginia Polytechnic Institute, Blacksburg 24061.

Effects of 0.5 mg/liter zinc (Zn) and snail grazing (400 snails/m2) on density of dominant algal and protozoan taxa, epilithic glucose respiration, and ash-free dry weight (AFDW) were examined using established (12-day colonization) periphyton communities in flow-through stream mesocosms with four treatments (Zn, snails, Zn and snails, control) for 30 days. Grazing and Zn similarly reduced the abundance of 5 of 10 dominant algal taxa and AFDW during the first 10 days of treatment. Abundance of these taxa and AFDW in grazed (ambient Zn) treatments approached control levels after 10 days as the effect due to snails decreased. Decreasing temperatures may have reduced snail activity. Snails, Zn, and the combination of these treatments contributed to higher rates of glucose respiration per unit AFDW. Protozoan species abundance was reduced to less than half by Zn but was unaffected by snails. Although Zn and snails individually altered structural and functional aspects of this microbial community, the effects when both treatments were combined could not always be inferred from the individual effects. Testing individual and combined variables that affect periphyton with a corresponding assessment of population dynamics, biomass, and community functional attributes will enhance understanding of the overall effects of pollutants on periphyton communities.

PMID: 3176034 [PubMed - indexed for MEDLINE]

High sensitivity bioassay of paralytic (PSP) and amnesic (ASP) algal toxins based on the fluorimetric detection of [Ca(2+)](i) in rat cortical primary cultures.

Beani L, Bianchi C, Guerrini F, Marani L, Pistocchi R, Tomasini MC, Ceredi A, Milandri A, Poletti R, Boni L.

Department of Experimental and Clinical Medicine: Section of Pharmacology, University of Ferrara, Via Fossato di Mortara 17-19, 44100, Ferrara, Italy. [email protected]

A high sensitivity bioassay able to recognise small amounts of paralytic and amnesic toxins in algal acetic extracts is described. The method is based on the measure of intracellular [Ca(2+)](i) in primary cultures of rat cortical neurones preloaded with Fura-2 and submitted to electrical field stimulation. Under normal conditions the basal [Ca(2+)](i) level was about 50-100 nM and was nearly doubled during the peaks induced by trains of electrical pulses at 10 Hz for 10 s. Saxitoxin (STX) 3.5 nM and tetrodotoxin (TTX) 24 nM halved the peaks height without affecting basal [Ca(2+)](i). Conversely, domoic acid increased the basal [Ca(2+)](i) (EC(50)=3. 7 microM) and decreased the calcium peaks (EC(50)=7.3 microM). CNQX (a competitive antagonist of AMPA/KA receptors) at 10 microM shifted to the right by a factor of 3 the concentration-response curves of domoic acid. The extracts of non-toxic algae were well tolerated by up to 10 microg protein/ml, whereas extracts of Alexandrium lusitanicum at 1-4 microg protein/ml reduced [Ca(2+)](i) peaks and increased basal calcium levels. This toxic effect of A. lusitanicum was unexpected since parallel HPLC analysis showed only the presence of gonyautoxins, known to act like saxitoxin. Therefore, the bioassay on rat cortical neurones revealed a complex composition of the toxins present in A. lusitanicum. The relevance of fluorimetric detection of [Ca(2+)](i) in primary neuronal cultures in the evaluation of algal risk is stressed.

PMID: 10736481 [PubMed - indexed for MEDLINE]

The effects of a purified toxic extract of Prymnesium patelliferum on transport of ions through the plasma membrane of synaptosomes.

Meldahl AS, Fonnum F.

Norwegian Defence Research Establishment, Division for Environmental Toxicology, Kjeller, Norway.

Extract of the ichthyotoxic marine alga Prymnesium patelliferum has been shown to have several different effects on the transport of neurotransmitters across nerve membranes. It inhibits the sodium dependent uptake of L-glutamate and GABA and enhances the calcium-dependent release of acetylcholine. We have therefore investigated the effects of a purified toxic extract of P. patelliferum on some membrane properties using rat brain synaptosomes. We found that under conditions where the algal extract inhibited the uptake of L-glutamate, it increased the intracellular concentrations of Na+ and Ca2+, stimulated efflux of K+ determined as 86Rb efflux, and depolarized the synaptosomal membrane. There was no effect on Na+/K(+)-ATPase or ouabain-insensitive ATPase activities. Further, there was no leakage of the cytosolic marker LDH, indicating that the various effects of the algal extract were not due to nonspecific leakage or lysis of the synaptosomes. The rise in the cytosolic concentration of free Ca2+ induced by the algal extract was dependent on extracellular Ca2+, and was inhibited by flunarizine (1-100 microM) but not by the Ca2+ channel blockers omega-conotoxin GVIA (1 microM), diltiazem (100 microM), nifedipine (100 microM) or verapamil (100-500 microM). The increase in Na+ influx induced by the algal extract was insensitive to tetrodotoxin (3 microM) and procaine (100 microM), whereas both the Na+ influx and the membrane depolarization were inhibited by flunarizine (1-100 microM). The increase in K+ efflux was insensitive to flunarizine (5-100 microM). From these results it appears that the toxic extract of P. patelliferum increases the permeability of synaptosomes to Ca2+, Na+ and K+ and that these effects may be responsible for the plasma membrane depolarization and the disturbance of the neurotransmitter transport processes.

PMID: 8533141 [PubMed - indexed for MEDLINE]

Toxic effects of water eutrophication on pancreatic, hepatic and osteogenic tissues of rats.

Novelli EL, Valente JP, Rodrigues NL.

Departamento de Quimica, Universidade Estadual Paulista, UNESP, Botucatu, Sao Paulo, Brazil.

Pollution, industrial solvents, concentrations of metals and other environmental agents are widely related to biochemicals values which are used in disease diagnosis of environmental toxicity. A rat bioassay validated for the identification of toxic effects of eutrophication revealed increased serum activities of amylase, alanine transaminase (ALT) and alkaline phosphatase (ALP) in rats that received algae, filtered water and nickel or cadmium from drinking water. Serum Cu-Zn superoxide dismutase activity decreased from its basal level of 40.8 +/- 2.3 to 26.4 U/mg protein, at 7 days of algae and at 48 hr of nickel and cadmium water ingestion. The observation that lipoperoxide concentration was not altered in rats treated with filtered water, while amylase, ALT and ALP were increased in these rats and in those treated with nickel or cadmium, indicated that pancreatic, hepatic and osteogenic lesions by eutrophication were not related to superoxide radicals, and might be due to a novel toxic environmental agent found in filtered and non-filtered algae water.

PMID: 7531373 [PubMed - indexed for MEDLINE]

Inhibitory effect of a toxic peptide isolated from a waterbloom of Microcystis sp. (Cyanobacteria) on iron uptake by rabbit reticulocytes.

Rojas M, Nunez MT, Zambrano F.

Departamento de Biologia, Facultad de Ciencias, Universidad de Chile.

The effect of a soluble toxin purified from the algae bloom of a eutrophic lake dominated by Microcystis on the receptor-mediated endocytosis of ferro-transferrin in rabbit reticulocytes was studied. The toxin was a very effective inhibitor of cell iron uptake. Kinetic studies using 125I, 59Fe-labeled transferrin indicated that the step of ferrotransferrin internalization was selectively inhibited by the toxin while the surface receptor-binding capacity, the externalization of previously internalized transferrin, and the cellular ATP levels were not affected. These findings indicate that the reduction of iron uptake caused by the toxin is due to inhibition of the internalization of surface-located transferrin-transferrin receptor complexes, perhaps due to a disruption of cytoskeleton integrity.

PMID: 2128422 [PubMed - indexed for MEDLINE]

Copper poisoning in sheep from North Ronaldsay maintained on a diet of terrestrial herbage.

MacLachlan GK, Johnston WS.

Copper toxicity occurred in North Ronaldsay sheep fed on a diet of terrestrial herbage relatively high in molybdenum. Five sheep were taken from the island of North Ronaldsay, Orkney to the veterinary investigation centre at Thurso and fed solely on the herbage of the laboratory paddocks, supplemented in winter by hay made from these paddocks. The level of copper, molybdenum, zinc and total sulphur in the terrestrial herbage was analysed, together with the seaweeds which form the major part of the diet on North Ronaldsay. Serum copper, vitamin B12 and serum aspartate aminotransferase levels were obtained. Four of the five sheep died on this diet of terrestrial herbage and had liver copper levels of 1379, 1723, 2279 and 2281 mg/kg. The susceptibility of the North Ronaldsay breed of Orkney sheep to copper poisoning when first introduced to a diet of purely terrestrial herbage is demonstrated by the high liver copper levels of the four dead sheep compared to the normal serum copper levels and unimpaired health of two other breeds of sheep and a north country Cheviot cross North Ronaldsay ram.

PMID: 7147642 [PubMed - indexed for MEDLINE]

Deaths from copper toxicity of sheep at pasture and the use of fresh seaweed.

Wiener G, Field AC, Smith C.

A number of sheep of the Orkney breed died of suspected copper poisoning while at pasture under circumstances which left sheep of other breeds apparently unaffected. Fresh seaweed offered to sheep with symptoms of copper toxicity appeared to be therapeutic and to lead to a reduction in plasma Cu level.

PMID: 595286 [PubMed - indexed for MEDLINE]

Study of impacts of treated wastewater to the Krka river, Slovenia.

Cotman M, Zagorc-Koncan J, Droic A.

National Institute of Chemistry, Ljubljana, Slovenia. [email protected]

Surface waters are used for disposal of treated effluents from wastewater treatment plants. These effluents usually contain only small amounts of various contaminants but these harmful components accumulate over time in the river, especially in sediments. An integrated approach for the evaluation of the impact of treated effluents was used to predict an ecological risk assessment to the Krka river beside Novo Mesto. The effluents from pharmaceutical and municipal wastewater treatment plants were discharged too closely into the receiving stream, so that separate impacts could not be distinguished. Biologically treated industrial effluents contained great amounts of barely biodegradable organic pollution, organic nitrogen, ammonia and phosphorus, and sometimes zinc. The toxicity of effluents was mostly dependent on their chemical composition. The municipal discharge contained greater amounts of organic pollution that was completely biodegraded but still had a great nutrient pollution load. The effluents were nontoxic. The harmful substances from the effluents were traced in the river. In the downstream site slightly higher concentration of organic pollutants, organic nitrogen, phosphorus, and zinc were detected due to discharges. The river water was over-saturated with oxygen, especially in the summer. In toxicity tests, samples of the river water were nontoxic. Sediments at the downstream site accumulated from discharged organic nitrogen, phosphorus, or zinc. The results of our study show that the main problem is eutrophication of the river Krka, so it is obvious we must reduce the quantity of nutrients in the effluents from wastewater treatment plants. In both effluents it will be necessary to reduce the polluting load of phosphorus, the limiting element for growth of algae and macrophytes in the receiving stream. In the industrial effluent it will be necessary to reduce substances which cause toxicity, such as zinc and nonbiodegradable organic compounds that may be accumulatec the water ecosystem over time.

PMID: 11700663 [PubMed - indexed for MEDLINE]

Statistical comparisons of the no-observed-effect concentration and the effective concentration at 10% inhibition (EC10) in algal toxicity tests.

Shieh JN, Chao MR, Chen CY.

Institute of Environmental Engineering, National Chiao Tung University 75, Po-Ai Street, Hisnchu, Taiwan 300.

Batch-type algal toxicity tests were conducted to evaluate the low toxic effects of metal toxicants. Both the no-observed-effect concentration (NOEC) and the effective concentration at 10% inhibition (EC10) were calculated and compared. The results of this study indicate that, for algal toxicity tests, NOEC offers better protection to the test organisms than EC10. In addition, the consistency of NOEC is found to depend on the response endpoints measured. A cut-off-value approach is proposed to determine whether NOEC or EC10 should be chosen for estimating low toxic effects. For a specific toxicity test, the average cut-off value directly indicates the magnitude of the square root of the within-group-variance. A precise test associated with small within-group-variances also produces relatively small average cut-off value (say, less than 10% of the growth reduction). This average value provides useful information on the minimum protection that can be offered by the NOEC.

PMID: 11380172 [PubMed - indexed for MEDLINE]

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