Redox-active molecules in bacterial cultivation media produce photocurrent

In recent years, global climate change has urged the importance of developing new clean energy technologies that may replace the combustion of fossil fuels and help to reduce carbon emissions. A promising method is the utilization of bacteria as electron donors in microbial fuel cells. In this work, we show that the cultivation media of bacteria that is based on yeast extract consists of redox-active molecules that can be used as electron donors reducing the electron acceptor Cytochrome C and producing an electrical current in a bio-electrochemical cell. We apply cyclic voltammetry and 2-dimensional fluorescence spectra to identify the redox active molecules NADH and Flavines that may play a key role in the electron donation mechanism. Finally, we show that upon illumination, the current production is enhanced.