Controlled depolymerization of cellulose by photoelectrochemical bioreactor using a lytic polysaccharide monooxygenase

In this article, we build a photoelectrochemical bioreactor by integrating a silicon photocathode with an AA9 lytic polysaccharide monooxygenase (LPMO)-based enzymatic system, where the 2,6-Dimethyl-1,4-benzoquinone (DMBQ) mediator acts as a linker. We emphasized the importance of regulating the supply of reductants and H2O2 in LPMO catalysis. Specifically, we verified that the reductant needs to be continuously produced in O2-driven LPMO catalysis, but it only serves as a trigger in H2O2-driven LPMO catalysis. Moreover, by appropriately regulating the lighting conditions, we can effectively adjust the supply of reductants, leading to an efficient and stable LPMO catalytic system during cellulose degradation. Therefore, this transformation scheme conceptually provides an environmentally-benign approach to convert cellulose into favorable chemicals sustainably by utilizing solar energy.