Microbial fuel cell: How bacteria can generate electricity

Bacillus stratosphericus is a bacteria that can generate electricity using a special battery called microbial fuel cell (MFC)

Bacillus stratosphericus can generate twice as much electricity as other types of common bacteria and can be used in a microbial fuel cell (MFC) to convert river waste into power and clean water. Scientists from Newcastle University believe they could be harvested and used in the developing world to power appliances.

Inside an MFC, the organisms produce carbon dioxide, protons and electrons when kept in a solution without oxygen.
Liberated electrons form a negatively charged anode while the protons create a positively charged cathode. This produces both charges necessary to produce an electric corrent. Selecting the best species of bacteria, scientists have been able to create an artificial biofilm, doubling the electrical output of the MFC from 105 watts per cubic metre to 200 watts per cubic metre.
Still is relatively low, but could be enough power to run an electric light and could provide a much-needed power source in parts of the world without electricity.