A new exciting research focus in our lab is to understand the molecular basis of the uptake of cathodic electrons in some bacteria both as catabolic electron donor and as reductant for autotrophic CO2 fixation to produce hydrocarbons or their biosynthetic precursors. This process is sometimes referred to as ‘bioelectrosynthesis’ and represents a novel, promising approach for microbial production of biofuels that does not involve biomass or photosynthetic microorganisms. In our molecular research we are focusing on the initial reactions of direct or indirect uptake of cathodic electrons into model microorganisms, as well as into novel microbial isolates.
We are currently working with several anaerobic microorganisms, including methanogens. One of our projects deals with the selection for a microbial community from a sewage digester plant for the production of methane in a biofuel cell. Instead of using expensive hydrogen, electrons for CO2 reduction are generated by hydrogen producing organisms in the community. Another approach is to generate reducing equivalents via the electrode of the biofuel cell and transferring them to the hydrogenases of the methanogens with the help of mediators. In the end, one can imagine producing CH4 from CO2 in a setup with a photoelectrode.