Synergistic dual-catalytic activity of lytic polysaccharide monooxygenase CaLPMO10 in enhancing waste biomass utilization

• Ca LPMO10 enhances the efficiency of both chitinase and cellulase. • Ca LPMO10 demonstrates a remarkable 620 % increase in the degradation of α-chitin when paired with the homologous chitinase Ca Chi18A_ΔChBDs. • Ca LPMO10 can oxidize and degrade the surface of various biomasses, reducing the crystallinity of resistant polysaccharides. • Ca LPMO10 significantly enhances the efficiency of Celluclast® 1.5L hydrolysis of pretreated sugarcane bagasse, achieving a synergistic effect of up to 113 %. • Ca LPMO10 and CelOCE display synergistic compatibility, jointly promoting the degradation of biomass by Celluclast® 1.5L. Efficient enzymatic saccharification of subtropical lignocellulosic biomass and aquatic processing waste is vital for sustainable biomass utilization. Lytic polysaccharide monooxygenases (LPMOs), particularly those in the AA10 family, play a pivotal role by synergizing with glycoside hydrolases to overcome the recalcitrance of polysaccharides. Here, we characterize Ca LPMO10, a dual-substrate AA10 enzyme from Chitinilyticum aquatile CSC-1, which exhibits broad substrate specificity and strong binding affinity—93.08% for phosphoric acid-swollen cellulose (PASC) and 95.97% for colloidal chitin (CC). In combination with Celluclast® 1.5L, Ca LPMO10 enhanced the degradation of microcrystalline cellulose, PASC, and carboxymethyl cellulose by 2.1-, 1.69-, and 2.35-fold, respectively. Remarkably, co-application with its native chitinase Ca Chi18A_ΔChBDs led to a 620% increase in α-chitin degradation. Structural analysis via SEM and XRD confirmed significant disruption of sugarcane bagasse, cassava pulp, and crab shells. Synergistic degradation of pretreated sugarcane bagasse by Ca LPMO10 and Celluclast® 1.5L yielded 16.21 mM of reducing sugars, a 113% increase relative to Celluclast® 1.5L alone, representing the highest enhancement effect reported to date for an AA10 enzyme. Furthermore, Ca LPMO10 exhibited excellent compatibility with the newly identified metallo-oxidase CelOCE, synergistically enhancing enzymatic hydrolysis. These findings underscore the broad applicability of Ca LPMO10 in the bioconversion of various biomass feedstocks.