Go Green: Scientists are One Step Closer to Developing Bacteria-powered Batteries

The future of clean energy is looking even brighter after scientists from the University of East Anglia announced in a press release on March 25, that they have discovered how bacteria transfer electricity into metals and minerals.

While scientists in the past knew the transfer of energy was possible and that it was done through special proteins on the surface of the bacteria, it has not been clear whether the proteins were working on their own or through an accomplice.

The new study, published in the journal Proceedings of the National Academy of Sciences, looks to the settle this question by examining Shewanella oneidensis, a member of a family of marine bacteria.

The team created a synthetic version of the bacteria using just the proteins in question. Once this was completed, they then inserted the proteins into the lipid layers of vesicles lipid membranes and tested how well electrons travelled between the electron donor on the inside and the iron-bearing mineral on the outside.

In doing so, the researchers discovered that, according to Clarke, "it is possible for the bacteria to lie on the surface of a metal or mineral and conduct electricity through their cell membranes." In other words, the bacteria was caught acting alone.

Among its many achievements, Clarke said that this study marks "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."

Biochemist Liang Shi of Pacific Northwest National Laboratory also participated in the study and believes the study brings scientists one step closer to understanding the way carbon moves through the environment.

"When organic matter is involved in reducing iron, it releases carbon dioxide and water," Shi said. "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."

Ultimately, Clarke envisions a future where cow manure is the new oil, thanks to the bacteria.

"These bacteria show great potential as microbial fuel cells, where electricity can be generated from the breakdown of domestic or agricultural waste products," he said.