Researchers from the University of Massachusetts Amherst evolved a new strain of the Geobacter microbe that increases power output per cell by 800%.
The hairy mud-loving microbe uses its hairlike filaments–called pili–to produce an electric current from both mud and waste water. The pili are only 5 nanometers in diameter (20,000 times smaller than a human hair); they’re also a thousand times longer than they are wide. But they are strong!
“This new study shows that output can be boosted and it gives us good insights into what it will take to genetically select a higher-power organism.” The work, supported by the Office of Naval Research and the U.S. Department of Energy, is described in the August issue of the journal, Biosensors and Bioelectronics.
The pili–usually called nanowires–have an amazing ability to shift electrons. Which is exactly how they create a current from waste and mud.
Creating a unique biofilm, they transfer the electron products to iron in both soil and waste. It’s the same process that allows bacteria to stick to your teeth but requires less flossing.
“In very short order we increased the power output by eight-fold, as a conservative estimate,” says Derek Lovley from the research team. “With this, we’ve broken through the plateau in power production that’s been holding us back in recent years.”
These findings open many doors for microbial fuel cell architecture and will hopefully lead to many applications beyond extracting electricity from crap.
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