Optimization of Medium Components for β-Glucosidase Production from Aspergillus Niger by Response Surface Methodology

β-Glucosidase is the key enzyme for the utilization of lignocellulose.But the commercial β-glucosidase can’t be produced. This paper focuses on the study of the β-glucosidase fermentation process.The fermentation medium components for β-glucosidase production from Aspergil lusniger was optimized by response surface methodology (RSM). Firstly, the three of the most important influence factors yeast extract, MnSO4•H2O and MgSO4•7H2O was obtained from Plackett-Burman design screening. Then the path of steepest ascent experiment was adopted to approach the optimal region of the medium composition. Lastly, the optimal concentration and mutual effect of three factors were predicted by RSM. The results showed that the best medium composition was Malt extract 18g/L, Yeast extract 3.22g/L, KH2PO4 3g/L, MnSO4•H2O 0.58mM, Tween-80 0.5mL/L and MgSO4•7H2O 0.23g/L. Under these fermentation conditions, the activity of β-glucosidase was up to 7.33IU/mL with increasing 23.2% than before.