Optimization of Fermentation Parameters for β-Glucosidase Production by Aspergillus niger

β-glucosidase produced by Aspergillus niger AS 3.4309 was carried out under Solid State Fermentation (SSF). The effects of medium composition and incubation conditions on the enzyme activity were investigated and suitable solid medium components and optimum incubation conditions for fermentation process were therefore established. The maximum β-glucosidase production (508 U g-1 dry matter) occurred after 72 h of incubation at 28°C in optimized solid medium containing wheat bran 100%, ammonium chloride 2%, MgSO4 7H2O 0.5% and KH2PO4 1.5% at the optimal conditions including moisture content of solid substrate 70% (w/w) initial pH 6.0 and inoculum level at 1x107 spores g-1 of solid substrate.