Findings published today in the journal Proceedings of the National Academy of Sciences (PNAS) show that proteins on the surface of bacteria can produce an electric current by simply touching a mineral surface.

The research shows that it is possible for bacteria to lie directly on the surface of a metal or mineral and transfer electrical charge through their cell membranes. This means that it is possible to ‘tether’ bacteria directly to electrodes – bringing scientists a step closer to creating efficient microbial fuel cells or ‘bio-batteries.’

The team collaborated with researchers at Pacific Northwest National Laboratory in Washington State in the US. The project was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the US Department of Energy.

Shewanella oneidensis (pictured) is part of a family of marine bacteria. The research team created a synthetic version of this bacteria using just the proteins thought to shuttle the electrons from the inside of the microbe to the rock.