Evaluation of agro-industrial by-products for α-galactosidase production by aspergillus oryzae in submerged culture

Several agro-industrial by-products (orange peel, soybean husk, bean husk and corn husk) were evaluated as carbon source to produce α-galactosidase by Aspergillus oryzae in submerged fermentation. Fermentations were carried out during 10 days at two temperatures (25 and 30°C) and three pHs (3.0, 5.0 and 8.0) to evaluate their effect on enzyme activity. For substrates that showed greater enzyme activity, the agitation effect on enzyme production was evaluated. The highest enzyme activity was obtained at 30 °C and pH 5.0 with soybean husk (33.96 U g^-1 protein) followed by corn husk (23.83 U g^-1 protein), Orange peel (10.68 U g^-1 protein) and bean husk (9.01 U g^-1 protein). Agitation showed an improvement in α-galactosidase production, giving an enzyme activity 1.4-fold higher than obtained with static soybean and corn husk culture.