UMass professor discovers electriciy-producing microorganism
By Dan O'Brien, Collegian Staff
October 14, 2003
Professor Derek Lovley of the University of Massachusetts Microbiology Department and postdoctoral researcher Swades Chaudhuri have discovered a microorganism that is capable of long-term electricity production, which could be an alternative source of energy in the near future.
The organism, Rhodoferax ferrireducens, is able to transfer electrons directly to an electrode as it metabolizes sugar into electricity. The electricity is produced by putting a wire between a microbe and an oxygen cell. This process collects the electron flow that otherwise would go directly to oxygen.
The application of this new energy source is still in its beginning stages. However, scientists have ideas concerning how the microorganism could be used to generate power. One idea is a tracking device for the government, explained Professor Lovely.
"It might be applied for something like a monitoring device for the Department of Defense, or possibly as an underwater tracking device, because it would be a lot easier to harvest the energy from that environment."
The researchers made their discovery by placing a bacteria and sugar with a graphite electrode in a closed glass container. When the bacteria began to eat the sugar, it came into contact with the electrode and began depositing electrons onto it.
When Lovley and Chaudhuri connected the electrode to another electrode exposed to the air, an electrical current began to flow.
Lovley also explained why there has been interest that considers using the microbes to generate electricity from sugar as an alternative to fossil fuels.
"There's been a lot of interest in microbial fuel cells trying to convert sugar into electricity," Lovley said. "But in the past, they've converted 10 percent or less of the available electrons, and we're up to over 80 percent."
The project began two years ago and was supported by the Office of
Naval Research and the Defense Advanced Research Projects Agency, as well as the U.S. Department of Energy.
Lovley explained that such attempts have been made before; however, the experiments resulted in little success. He said that previous experiments have required an electron shuttle between the sugar and oxygen. Unfortunately, this poses a potentially toxic situation for humans.
"People have done it without an [electron shuttle] before, but their recovery of energy was less than one percent."
The discovery by Lovley and Chaudhuri is receiving a good amount of press. The researchers have been interviewed by the Boston Globe, The New York Times and Science magazine. Most notably, their findings have appeared in the October issue of Nature Biotechnology.
The first step of this project has been considered a success; however,
Lovley said it might be some time before the energy source can be used commercially.
"There are still issues with getting a high enough voltage and converting the sugar to electricity fast enough," he said. "Although the process is highly efficient, it is slow. And as the process is right now, we're not talking about a lot of power. It's barley enough to run a calculator."
Although this new finding cannot be used to power up your lawnmower or cell phone today, much progress has been made in the area of microbiological fuel cells.
"I don't want to give the impression that it's 'Back to the Future,' where we stuff a banana in the engine and go, but it's a pretty good leap from where microbial fuel cells were before," Lovley said.
