Evaluating the Feasibility of Microbial Electrosynthesis Based on Gluconobacter oxydans

Primary microbial electrochemical technologies are utilizing the interfacing of microbial redox reactions and electrodes. Based on its exploitation as recognition element for bioelectrochemical glucose sensors and inspired by its biotechnological potential Gluconobacter oxydans was studied on its suitability for microbial electrosynthesis. It is demonstrated that in bioelectroreactors the conversion of glucose by G. oxydans based on mediated extracellular electron transfer is not related to electric current flow. Oxidation current can only be recorded after preceding aeration phase, but the response does strongly depend on the microbial activity status, pO2 and gas supply as well as the pH regime. It is proven that the electric current is derived from the microbial cells, but the mechanism still needs to be elucidated. The suitability of G. oxydans for microbial electrosynthesis but also for bioelectrochemical sensors is critically assessed.