Studies on the Preparation of Immobilized Enzymes oy Radiopolymerization

Part VII. Preparation of bead shaped glucoamylase and its characteristics

Abstract

Glucoamylase(E.C 3. 2. 1. 3., α-1, 4-glucan glucohydrolase)was immobilized in a bead shape (0.5-1mm diameter) by radiopolymerization method under the frozen temperature(-86°C). The characteristics of the immobilized enzyme were investigated and the enzyme column was operated continuously, 1). The optimum reaction pH was 4.7 for native enzyme and 4.2 for immobilized one. 2). The smallest bead had the highest retained activity (67.5%) when soluble starch (Merck, Zulkowsky)was used as a substrate. 3). There was no big differences in the optimum reaction temperature between native and immobilized glucoamylase. 4). Km value of immobilized enzyme was 2.6 times(maltose as a substrate)or 7.3 times(soluble starch, Merck for analysis, as asubstrate)higher than that of native enzyme. 5). Liquified starch(5.5% solution) was passed through the column (flow rate SV 2.3) in which bead shaped glucoamylase was packed and hydrolyzed to 94%.
At the fixed flow rate (SV 1.36), starch solution was hydrolyzed (over 90%) continuously up to 60 hours.