Microbial fuel cell-based biosensor for monitoring anaerobic biodegradation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

•The anaerobic biodegradation of P34HB films was investigated in MFC system.•Anaerobic biodegradability of P34HB films was evaluated by the coulombic yield biodegradability parameters.•The anaerobic biodegradation of P34HB films occurred via surface erosion.•Microbial community of anode biofilms and the surface of P34HB films was studied.