1-35: Butanol production enhancement by electroactive Clostridium sp. in bioelectrochemical system

Here, we showed one electroactive Clostridium strain directly accepted electrons from a cathode in bioelectrochemical system (BES). Electrochemically active Clostridium sp. was cultivated with glucose 20 g/L in a cathode compartment at an applied potential of -160 mV vs. Ag/AgCl. Interestingly, few amount of gas was generated but butanol was increased almost twice in BES. Images of scanning electron microscopy and confocal laser scanning microscopy suggested the active interaction between cathode and biofilm. Cyclic voltammery indicated only biofilms had electroactivity but no supernatant. The current was increased by maturing biofilm and the ratio of NAD⁺/ NADH indicated direct reduction of NAD⁺ by a cathode. It was suggested that electroactive Clostridium strain directly accepted electrons from a cathode and it more produced reduced chemicals like butanol.