Bacteria that use sugars and sewage as fuel are being investigated as a pollution-free source of electricity. They feed by plucking electrons from atoms in their fuel and dumping them onto the oxygen or metal atoms in the mixture. The transfer of the electrons creates a current, and connecting the bacteria to an electrode in a microbial fuel cell will generate electricity, although not necessarily very efficiently.

A clearer understanding of the way bacterial nanowires form should allow engineers to make more efficient and powerful biological fuel cells, Gorby says. For example, they could ensure that the chemical conditions surrounding bacteria encourage it to grow as many nanowires as possible, increasing conductivity.