Optimization of Cellulases under Solid State Fermentation by Newly Isolated Fungus: An Environmentally Sustainable Approach

There exists a substantial interest in advancing the commercial production of cellulolytic enzymes. This drive is fueled by the pursuit of cost-effective substrates and energy-efficient fermentation processes, all aimed at enhancing the economic viability of enzymatic conversion of lignocellulosic biomass (LB) into bioethanol. In the present study, emphasis was given to the isolation of superior cellulase-producing fungal isolate. A comprehensive collection of 199 fungal isolates was derived from diverse soil samples, and the fungal isolate with the largest hydrolytic halos was identified as Trichoderma atroviride AD-130 through molecular analysis. The potential of cellulase production was explored and optimized during solid state fermentation (SSF) using inexpensive substrates such as Eichhornia crassipes and Municipal Solid Waste (MSW). Trichoderma atroviride AD-130 displayed the maximum cellulase production on the fifth day at pH 7.0 at a substrate-moisture ratio of 1:6 for E. crassipes and 1:2 for MSW under solid-state fermentation. The cellulases obtained were partially purified and characterized for their optimal pH (6.0, 4.5, and 5.0 for FPase, CMCase, and BGL respectively) and temperature conditions (60°C, 50°C, and 70°C for FPase, CMCase, and BGL respectively). Zymogram analysis revealed that the cellulolytic fungus T. atroviride AD-130 possessed multiple alleles for the synthesis of CMCase, which is crucial for the effective degradation of various types of lignocellulosic substrates.