Derek Lovley, from the University of Massachusetts Amherst recently experimented with a microbe named “Geobacter”, who loves to live in sediments and mud, and whose hairlike filaments can produce electricity from the muddy environment it loves to live in.
His findings open new perspectives to improved microbial fuel cell architecture and should lead to “new applications that extend well beyond extracting electricity from mud,” as he says. “In very short order we increased the power output by eight-fold, as a conservative estimate,” says Lovley. “With this, we’ve broken through the plateau in power production that’s been holding us back in recent years.”
Geobacter’s hairlike pili are very thin, of about 3 to 5 nanometers in diameters (20,000 times thinner than human hair), but nevertheless strong. The researchers named them “nanowires”, for their role in moving electrons. Using their pili, Geobacters produce electricity from organic waste and sediments. The pili has yet another role: keeping the biofilm together, because the biofilm helps transfer the produced electricity to the iron in soil and sediment. In their natural living environment, Geobacter colonies form gluey biofilms that anchor onto a surface such as a tooth or an underwater rock, providing a living environment near a food source.
Geobacter was initially used in 1987 as a soil decontamination agent by Lovley and other scientists, and was discovered in the Potomac river. It can decontaminate soils because it processes iron and other metals in the way we breathe oxygen. One Geobacter microbe wouldn’t produce much electricity, but colonies of them could make a difference when we would infest muddy waters with them. The property of producing electricity was only discovered in 2005. Again, I guess any play with microbes and bacteria are hazardous – that’s my personal opinion and fear.