Purification and characterization of a novel β-glucosidase from Aspergillus flavus and its application in saccharification of soybean meal

y Aspergillus flavus has been regarded as a potential candidate for its production of industrial enzymes, but the details of beta-glucosidase from this strain is very limited. In herein, we first reported a novel beta-glucosidase (AfBglA) with the molecular mass of 94.2 kDa from A. flavus. AfBglA was optimally active at pH 4.5 and 60 degrees C and is stable between pH 3.5 and 9.0 and at a temperature of up to 55 degrees C for 30 min remaining more than 90% of its initial activity. It showed an excellent tolerance to Trypsin, Pepsin, Compound Protease, and Flavourzyme and its activity was not inhibited by specific certain cations. AfBglA displayed broad substrate specificity, it acted on all tested pNP-glycosides and barley glucan, indicating this novel beta-glucosidase exhibited a beta-1, 3-1, 4-glucanase activity. Moreover, the AfBglA could effectively hydrolyze the soybean meal suspension into glucose and exhibit a strong tolerance to the inhibition of glucose at a concentration of 20.0 g/L during the saccharification. The maximum amount of the glucose obtained by AfBglA corresponded to 67.0 g/kg soybean meal. All of these properties mentioned above indicated that the AfBglA possibly attractive for food and feed industry and saccharification of cellulolytic materials.