Solid-state fermentation of spent mushroom substrate through a synergistic fungal consortium for enzymatic cocktail production

This study aimed to develop a cost-effective and efficient enzymatic cocktail from spent mushroom substrate (SMS) while serving as a model to understand fungal-fermentative communities and characterize microbial diversity stability in SMS valorization. Co-cultivation of Aspergillus fumigatus IMCC2006 and Trichoderma asperellum IMCC2012 was optimized for cellulase production under varying moisture, pH, and fermentation time. Optimal enzyme yields were achieved at 60 % moisture, pH 5, and 96 h of fermentation, producing maximum CMCase (11.5 U g −1 ) and FPase (4.35 U g −1 ) activities, while the highest xylanase activity (13.8 U g −1 ) occurred at 70 % moisture. Scanning electron microscopy and FTIR confirmed the consortium's cellulolytic capability in SMS degradation. Microbial community analysis revealed Proteobacteria and Firmicutes dominance at the end of fermentation, supporting system stability. The findings provided a plausible solution for valorization of agricultural residues for enhanced enzymatic production from the synergistic consortium, to catalyze biorefinery applications. • Raw spent mushroom substrate was an effective option for enzymatic cocktail production. • Significance of fungal co-culture for cellulase production through solid-state fermentation. • Influence of moisture and fermentation time in the optimization of cellulase production. • The diversity of bacterial community in fermented spent mushroom substrate was assessed.