A lot of recent news revolves around green energy, and it appears that the pursuit of clean electricity just got another boost, this time thanks to bacteria.
The findings by scientists at the University of East Anglia were published on Monday March 25 in the journal Proceedings of the National Academy of Sciences (PNAS), and indicate that proteins located on the surface of bacteria have the ability to create an electric current through contact with a mineral surface. This means that it is possible for bacteria to generate electricity by lying on top of a metal or mineral. Bacteria can then be directly 'tethered' to electrodes, making it more possible for scientists to make "bio-batteries," or microbial fuel cells.
"This is the first time that we have been able to actually look at how the components of a bacterial cell membrane are able to interact with different substances, and understand how differences in metal and mineral interactions can occur on the surface of a cell," says lead researcher Dr. Tom Clarke of UEA's school of Biological Sciences. "These bacteria show great potential as microbial fuel cells, where electricity can be generated from the breakdown of domestic or agricultural waste products."
The researchers came to their conclusions by creating a bubblelike network of fatty molecules dotted with membrane proteins that imitated the cell membrane of Shewanella bacteria. The bubbles, which harbored an electron donor, were then exposed to an iron-containing mineral. The researchers then measured the speed of the electrical current that traveled across the membrane, which proved to be very fast.
The findings have important implications for the development of bio-batteries that would be able to keep energy for sensors in isolated environments. Additionally, electricity could be charged into the bacteria, resulting in the creation of useful materials. It also helps us better understand how carbon operates in the oceans, land and atmosphere.
"When organic matter is involved in reducing iron, it releases carbon dioxide and water," says biochemist Liang Shi of Pacific Northwest National Laboratory. "And when iron is used as an energy source, bacteria incorporate carbon dioxide into food. If we understand electron transfer, we can learn how bacteria controls the carbon cycle."
The research project obtained funding through the Biotechnology and Biological Sciences Research Council (BBRSC) and the U.S. Department of Energy.
