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

Abstract

Poly-3-hydroxybutyrate-co-4-hydroxybutyrate (P34HB) polymer, which is a common type of polyhydroxyalkanoates (PHAs), may provide alternative solutions to the white pollution issues. In this study, its anaerobic biodegradation was investigated through the microbial fuel cell (MFC) system, by monitoring several parameters, including the time-dependent changes in the electrical signals, the concentration of the P34HB degradation products, biogas production, the weight loss of P34HB films, and the morphological and chemical structure of the test materials during the degradation. Notably, the electrical signal was selected as an indicator to online monitor the anaerobic biodegradation of P34HB films. After 40 days of degradation, the coulombic yield biodegradability (Q-biodegradability) of P34HB films reached 37.59%. A linear relationship among the weight loss biodegradability of P34HB films and Q-biodegradability with high correlation coefficient of R2 = 0.998 was established. The results suggested that the anaerobic biodegradability of P34HB films can be efficient measured by using the Q-biodegradability compared to conventional methods. Microbial community analysis also indicated that the genus Desulfovibrio and Enterobacter contributed to the biodegradation of P34HB films and the electrical signals production via the cooperation among other microorganisms. This study presented the online monitoring of the anaerobic biodegradation of P34HB films through MFC-based sensors, which provided an alternative approach to evaluate the anaerobic biodegradability of biodegradable plastics.