A Lytic Polysaccharide Monooxygenase from a White-Rot Fungus Drives the Degradation of Lignin by a Versatile Peroxidase

The enzymatic biodegradation of structural polysaccharides is affected by the degree of delignification of lignocellulose during the white-rot fungal decay process. The lignin matrix decreases accessibility to the substrates for LPMOs. H2 O2 has been studied as a cosubstrate for LPMOs, but the formation and utilization of H2 O2 in the reactions still represent an intriguing focus of current research. Lignin-degrading peroxidases and LPMOs usually coexist during fungal decay, and therefore, the relationship between H2 O2 -dependent lignin-degrading peroxidases and LPMOs should be considered during the wood decay process. The current study revealed that white-rot fungal LPMOs may be involved in the degradation of lignin through driving a versatile form of peroxidase activityin vitro and that H2 O2 generated byPo LPMO9A was preferentially used for lignin oxidation by lignin-degrading peroxidase (Ps VP). These findings reveal a potential relationship between LPMOs and lignin degradation, which will be of great significance for further understanding the contribution of LPMOs to the white-rot fungal decay process.