Research breakthrough in microbial fuel cell converts waste to energy
November 20 2008 / by Garry Golden
Category: Energy Year: 2018 Rating: 4 Hot
What happened?
Researchers at the University of Minnesota-Twin Cities believe they have found a unique species of bacteria, Geobacter sulfurreducens, that can convert wastewater organic compounds into electricity using a low cost carbon (graphite) electrode.
“Other species of bacteria may produce just as many electrons as they oxidize available fuels, but their cell membranes act like an insulator for electron transport,” said Daniel Bond, a microbiologist at the University of Minnesota-Twin Cities. “With Geobacter, it’s the difference between a rickety one-land bridge and a modern 12-lane highway. The electrons pass easily through internal membranes and cell walls and hop onto the electrode.” As each “hop” requires them to travel about 10 Angstroms.
Geobacter has proteins that guide electrons all the way to the electrode. “This makes Geobacter unique in comparison to other bacteria,” Bond said. “Because of the distances involved, we know that multiple proteins are involved, which adds to the complexity and why we can’t just clone a gene into E. coli to do this.”
Why is this important to the future of energy?
While traditional batteries and fuel cells often use expensive precious-metal catalysts (e.g. platinum) to strip electrons off the fuel source to generate electricity, microbial fuel cells use biological agents to do the heavy work.
A microbial fuel cell based on Geobacter would require only an inexpensive form of carbon (graphite) to help the bacteria transfer electrons onto the surface of electrodes. This novel design of microbial fuel cells could be scaled to efficiently convert waste organic matter (e.g. sewage, food waste) to electricity.
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