Starch conversion by immobilized glucoamylase

Abstract

Abstract Glucoamylase bound to DEAE‐cellulose in 0.05 M sodium acetate, pH 4.0, is active in the conversion of starch to glucose. The activity of the DEAE‐cellulose‐bound enzyme ranges from 16 to 55% of the activity of the free enzyme. Binding of the enzyme narrows the pH optimum to approximately 4.0 and lowers the temperature optimum to 40–50°C as compared to a 60°C temperature optimum for the free enzyme. Concentrations of acetate buffer above 0.1 M disrupt the DEAE‐cellulose‐enzyme complex. Columns were used with some success for the continuous conversion of starch. Pretreatment of the starch with α‐amylase and clarification were necessary to prevent blocking of the column. Columns maintained activity for more than 3 weeks of continuous operation.