Optimization of Fermentation Conditions for Enhanced beta-GIucosidase Production from CeUulolytic Aspergillus terreus Strain PPCF using Agro-Residues

摘要

Lignocellulosic biomass represents a promising option as carbon source the cellulase enzyme production but most of the microbial cellulases have been reported with low p-glucosidase activity. Efforts were, therefore made in the present study for the selection of an efficient P-glucosidase producing fungal strain and optimization of fermentation conditions for the enzyme production using wheat bran as a sole carbon source. The Carboxy methyl cellulose hydro-lyzing fungus showing maximum extracellularbeta-glucosidase activity (0.517 Uml~(-1)) in crude culture filtrate was selected and identified as Aspergillus terreus PPCF by 5.8S ITS rRNA- gene sequencing. An increase in enzyme activity from 0.517 Uml~(-1) to 1.19 Uml~(-0) was achieved in 7 dunder optimized liquid conditions (pH 7.0) using wheat bran (3%) w/v) as sole carbon source and ammonium sulfate (0.5% w/v) as nitrogen source with 8% inoculum size (CFU 3.2 x 10~8 ml~(-1)) at 27 ± 2°C. During solid-state fermentation with 1:7 solid to a liquid ratio the enzyme activity was further enhanced to 2.01 Uml~(-1). Solid state fermentation utilizing agro-wastes as natural-substrate is an appropriate cost-effective technique for fungal enzyme production that directly emphasizes on the management ofagricultural solid waste. The study also suggests wheat bran as an appropriate substrate for com-mercial enzyme production that can be used for cellu-losic bioethanol production.