Preparation and characterization of amyloglucosidase adsorbed on activated charcoal

Amyloglucosidase (AMG) [alpha-1, 4-D-glucan glucohydrolase (E.C.3.2.1.3)] is an exo-enzyme, which is used in the hydrolysis of starch to glucose in industries. To increase the efficiency and profitability of this process, AMG was immobilized on activated charcoal by physical adsorption without the aid of any cross-linking agent, characterized by hydrolysis of dextrin and compared with the native enzyme. The immobilized enzyme has 90% catalytic activity of the native enzyme. Optimum pH of the immobilized enzyme was six, which shifted to basic side by one unit when compared to the optimum pH of the native enzyme (5.0). Optimum temperature of the immobilized enzyme was 60 degrees C, decreased by 10 degrees C when compared to optimum temperature (70 degrees C) of the native enzyme. K-m(app) and V-max(app) values of immobilized enzyme were found to be 1.0 x 10(-3) g/l and 3.8 x 10(-4) g/min/unit of enzyme, respectively which were less than the values of the native enzyme. The immobilized system can be used repeatedly and continuously for a longer period of time. (C) 2000 Elsevier Science S.V. All rights reserved.