Production optimization and properties of beta glucosidases from a marine fungus Aspergillus-SA 58

Abstract

Aspergillus strain SA 58, showing considerable beta glucosidase production was selected as the potential strain. The fungus showed enzyme production in both acidic and alkaline pH. A temperature of 35 degrees C was found to be optimum for enzyme production. Maximum enzyme production was seen when pectin was used as the carbon source (80 U/ml). In solid-state fermentation, an enzyme production of 6200 U/g Initial Dry Substrate was noted. The strain produced two extra cellular enzymes and two intra cellular enzymes. For both the extra cellular enzymes (BGL A and BGL B), 60 degrees C was found to be optimum temperature for activity. BGL A showed an optimum pH of 4.0 while BGL B showed an optimum pH of 3.0 for activity. Both the enzymes showed a second peak of activity at pH 9.0. Both BGL A and BGL B showed high thermal stabilities with residual activities of 86% and 85% even after 6 h of incubation at 50 degrees C.