Chitin-active lytic polysaccharide monooxygenases and its synergistic effect with chitinases

Chitin, the second most abundant biopolymer in nature, exhibits diverse biological activities and substantial application prospects. Nevertheless, the inherent recalcitrance of its polysaccharides poses significant challenges to effective utilization. Conventional techniques for chitin utilization have raised concerns regarding environmental protection and resource efficiency, necessitating the exploration of novel approaches. Biological enzymatic degradation of chitin, particularly through the action of lytic polysaccharide monooxygenases (LPMOs), has emerged as a promising strategy for its efficient and environmentally sustainable utilization. LPMOs facilitate the oxidative degradation of biopolymers, thereby enabling the efficient and eco-friendly conversion of biomass resources. Herein, we comprehensively reviewed the research progress in the origin, classification, reaction mechanism, influencing factors, product characteristics of chitin-active LPMOs discovered so far, and its synergistic effects with chitinases were further introduced. This review provides thorough understanding of the role of chitin-active LPMOs in chitin degradation, and lays a solid theoretical foundation for the future development of more potent chitin-converting enzymes or enzyme cocktails in biotechnology applications.