Bacillus stratosphericus is the name of a bacterium that is commonly found in high concentrations in the stratosphere. This bacterium was recently in news as the researchers have developed a new ‘super’ biofilm in which this microbe is a component. This microfilm can be used as a Microbial Fuel Cell (MFC), thus making it a potential source of energy. The bacteria was brought down to Earth as a result of atmospheric cycling processes and isolated by the team at New Castle university from the bed of the River Wear.
Use of Microbes in Electricity Generation
Use of microbes to generate electricity is not a new concept and has been used in the treatment of waste water and sewage plants. The Microbial fuel cells, which work in a similar way to a battery, use bacteria to convert organic compounds directly into electricity by a process known as bio-catalytic oxidation. A biofilm — or ‘slime’ — coats the carbon electrodes of the MFC and as the bacteria feed, they produce electrons which pass into the electrodes and generate electricity. Until now, the biofilm has been allowed to grow un-checked but this new study shows for the first time that by manipulating the biofilm you can significantly increase the electrical output of the fuel cell. Inside an MFC, the bacteria 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 current.