Correlation and synergy between fungal secretome cellulolytic enzyme cocktails and commercial cellulase for woody biomass degradation

Cellulolytic enzymes for bioconversion of lignocellulose to fermentable sugar provide an economically viable solution for numerous biofuels production, but currently problematic due to the high cost of commercial cellulase. It has been assessed the secretome of full cellulase and hemicellulase, as well as auxiliary enzyme activity, were assessed in 17 fungal strains. The breakdown of pretreated poplar with various crude enzymes was investigated, and the synergistic effects of crude enzymes and commercial cellulase were evaluated. Correlation coefficients between different enzyme activities and glucose hydrolysis from pretreated poplar were also discussed. It was found cellobiohydrolase and xylanase activity were positively correlated with glucose release, but β-glucosidase activity was indeterminate and lysis polysaccharide monooxygenase activity had a poor correlation. The highest cellulose conversion rates from the pretreated poplar utilized commercial cellulase LLC02 combined with Trichoderma reesei ATCC 24449, Aspergillus niger SM24 and Aspergillus niger SM751 were 94.8 %, 91.6 %, and 103.6 %, respectively. These findings demonstrate the fact that coupling an appropriate amount of secretome cellulolytic enzyme cocktail with cellulase boosts woody biomass hydrolysis, implying that crude enzyme cocktails from selected fungal strains have a high potential for minimizing commercial cellulase costs for industrial applications.