Unlocking sustainable biomass conversion: Enhanced cellulose degradation by a mutant Trichoderma viride JC-1U7

Abstract

Cellulose degradation is a critical process for sustainable biomass conversion, yet finding efficient microbial strains remains a challenge. Current industrial processes often rely on harsh chemical treatments or less efficient enzymatic systems. In this study, we isolated and characterized a novel Trichoderma viride JC-1, which exhibits high cellulolytic activity. Through ultraviolet (UV) mutagenesis, we generated a mutant strain JC-1U7, with enhanced cellulose-degrading capabilities. The mutant strain demonstrated significant improvements in filter paper activity (FPA), endoglucanase (CMCase), and exoglucanase (pNPCase) activities, with FPA reaching 0.49 U/mL on day 8, CMCase peaking at 3.3 U/mL on day 6, and pNPCase achieving 0.11 U/mL on day 8. Molecular docking and dynamics simulations revealed the structural basis for the enhanced 1,4-β-D-glucan glucanohydrolase,1,4-β-D-glucan cellobiohydrolase, and β-1,4-glucosidase enzymatic activity, highlighting the critical roles of key amino acid residues in substrate binding and catalysis. The optimal conditions for Forestry waste's (PPGL) cellulose degradation by strain JC-1U7 were determined to be an inoculum volume of 5 %, pH 5, and a temperature of 25 °C for 8 days. These findings underscore the potential of strain JC-1U7 as a robust biocatalyst for sustainable biomass conversion, offering insights into the molecular mechanisms underlying its cellulolytic efficiency.