Coupling of CO Electrolysis with Parallel and Semi-Automated Biopolymer Synthesis - Ex-Cell and without Downstream Processing.

Important improvements have been achieved in developing the coupling of electrochemical CO reduction to formate with its subsequent microbial conversion to polyhydroxybutyrate (PHB) by Cupriavidus necator. The CO based formate electrosynthesis was optimised by electrolysis parameter adjustment and application of Sn based gas diffusion electrodes reaching almost 80 % Faradaic efficiency at 150 mA cm. Thereby, catholyte with the high formate concentration of 441±9 mmol L was generated as feedstock without intermediate downstream processing for semi-automated formate feeding into a fed-batch reactor system.

From CO to Bioplastic - Coupling the Electrochemical CO Reduction with a Microbial Product Generation by Drop-in Electrolysis.

CO has been electrochemically reduced to the intermediate formate, which was subsequently used as sole substrate for the production of the polymer polyhydroxybutyrate (PHB) by the microorganism Cupriavidus necator. Faradaic efficiencies (FE) up to 54 % have been reached with Sn-based gas-diffusion electrodes in physiological electrolyte. The formate containing electrolyte can be used directly as drop-in solution in the following biological polymer production by resting cells.