A team of ten students at Bielefeld University, Germany have come up with a new source of electricity – the infection-causing bacteria Escherichia coli. Their ground-breaking technology uses the bacteria to convert glucose into energy. The team hopes that the bacteria-powered batteries might prove to be a viable form of renewable energy, and will present their project at this year’s international Genetically Engineered Machine competition (iGEM) at the Massachusetts Institute of Technology (MIT) in Boston, USA.
MFCs (Microbial fuel cells) work in much the same way as conventional batteries, but with one difference. An MFC consists of two separate units, the anode and the cathode components, just like the batteries now in current household use, and a partly permeable membrane separates the two areas. But in contrast to conventional batteries, however, there are bacteria in the anode area of the bio-battery instead of electrolytes. These break down substrates, in this case glucose, in a metabolic process. This produces electrons that after starting from the anode are finally delivered in an external loop to the cathode. The external circuit is then the one with the battery-powered application, for example, for lights or small motors. In this way, bacteria can produce electric energy.
One of the team members, Thorben Meyer explains how sustainable this method of producing electricity can be: “There is an ever-increasing demand for sources of alternative energy. The conservation of fossil fuels and the phasing out of nuclear energy in Germany have sped this process up.’ Another consideration was the environmental pollution caused by conventional batteries. ‘It is not only large-scale electricity production which pollutes the environment, but also household batteries, which contain many harmful substances. Heavy metals and dangerous inorganic and organic electrolytes can be released into the environment by improper handling of batteries.”