Microbial fuel cell-mediated lignin depolymerization: a sustainable approach

Background A microbial electrochemical cell was designed for lignin depolymerization. Alkali-extracted wheat straw lignin was used as catholyte in a microbial fuel cell and operated for six days. At the cathode, lignin was depolymerized by H2O2, produced during microbial fuel cell operation. Results The power density reached its maximum over two to three days (0.58 mu W cm(-2)), and declined thereafter. Fourier transform infrared analysis of the residual lignin indicated the cleavage of C-O-C (beta-O-4) bonds without disturbing the phenolic ring structure and high-power liquid chromatography analysis confirmed the presence of vanillin in the depolymerized sample. Conclusion The proposed strategy involves a self-sustainable microbial electrochemical process to convert complex lignin into low molecular weight value-added aromatic chemicals such as vanillin. (c) 2018 Society of Chemical Industry