Optimization of Exoglycosidase Medium Produced by Aspergillus niger 3.316 and Its Enzymology Properties

The enzymatic activity of exoglucanase was used as an indicator. The medium components of exoglucanase produced by Aspergillus niger were optimized, and the enzymatic properties of exoglucanase were studied. The single factor and response surface method for the optimization of the conditions for exogenous dextranosidase production by Aspergillus niger 3.316 showed that the optimal medium components were:Wheat straw 14.73 g/500 mL, ammonium sulfate 2.22 g/500 mL, microcrystalline fiber and maltose 2.18 g/500 mL. Under there condition, the exoglucanase was 2.120 U/mL, and the enzyme activity was increased by 91% compared with that before optimization. The optimal temperature for exoglucanase was 50℃. Exoglucanase had higher thermal stability at 50℃. Exoglucanase exhibited higher stability at pH3.0 and 7.0. Exodextranosidase could play a role in high temperature and acid environment, participate in the efficient degradation of cellulose in high-temperature acidic environments, improve productivity, and use the decomposed glucose for fermentation at the same time, which would have the potential to apply high-temperature Daqu fermentation wine production.