Preparation and Characterization of Cross-Linked Enzyme Aggregates of Amyloglucosidase

摘要

Cross-linked enzyme aggregates of glucoamylase (GAs-CLEAs) were prepared. The effect and concentration of aggregating agent as well as those of cross-linking agent were studied. It was effective for GAs-CLEAs production to use ammonium sulfate (80 %-saturation), and subsequently cross-link for 2 h with 4.5 % (v/v) glutaraldehyde. Some changes in optimum pH and temperature values of the enzyme activity were recorded after immobilization. Moreover, the thermal stability of the resulting GAs-CLEAs was also investigated. Compared to the free enzyme, the GAs-CLEAs exhibited the expected increasing thermal stability. These CLEAs are suitable for all starch-based industries. To the best of our knowledge, this is the first report of immobilization of GAs as cross-linked enzyme aggregates.