Synergistic action of lytic polysaccharide monooxygenase with glycoside hydrolase for lignocellulosic waste valorization: a review

Improving enzymatic saccharification of lignocellulosic biomass is the major bottle neck in the area of second generation biofuel production. Metalloenzyme lytic polysaccharide monooxygenase (LPMO) has the capability to oxidize the complex lignocellulose in the crystalline area and thus acts as a catalyst in the process of lignocellulosic deconstruction. The present review undermines the importance of LPMO in biofuel sectors. It emphasizes evolutionary relationship, structure, mechanism, and synergistic action of LPMOs. A radial phylogram of 168 LPMO genes from archaea to terrestrial plant infers their evolution in different domains. The existence of LPMOs in extreme environmental condition and structural insights of these LPMOs show the conservation in active copper center and flat surface for substrate binding. This finding may open a new way for the isolation of active LPMOs from different environmental condition and their optimization to withstand the industrial parameters. The synergistic action of LPMO with different cellulase and hemicellulase may help in lowering the catalytic load which ultimately may reduce the cost of pretreatment steps. This review therefore sums up the recent findings concerning the LPMO’s mechanism of action and identifies issues and questions to be addressed in the future.