Abstract
Endo (1?4) ß-D-glucanase [EC 3.2.14] is a type of cellulase, which randomly cleaves the ß (1?4) glycosidic linkages in cellulose polymer chain. It is widely used in different industries such as, biofuel, food, textile, paper and pulp industries. There are several limitations in using soluble enzymes in industrial processes, for instance, they show low stability under harsh operational conditions and the enzyme recovery becomes difficult for continuous use. Immobilization technology is one of the solutions that not only overcome the aforementioned problems, but also makes the process more cost effective. Therefore, the current study was designed to study the effect of immobilization using the entrapment technique for endo (1?4) ß-D-glucanase from B. licheniformis KIBGE-IB2. For this purpose, nontoxic, non-protein reactive bio-polymer agar-agar was used. A maximum immobilization yield of 66.0% was achieved at 2.0 g% (w/v) agar-agar. The immobilized enzyme exhibited broader pH and temperature activity profile as compared to soluble enzyme. The temperature optimum of the soluble enzyme was found to be 60°C and it shifted to 70°C after entrapment. Optimal pH for both the systems remains unchanged (pH-6.0). The immobilized enzyme shows greater thermal stability in the range of 50°C to 80°C, with reference to soluble enzyme. The entrapped enzyme in agar-agar matrix retained its activity for 8 successive cycles. The results indicate a possibility of employing matrix entrapped endo (1?4) ß-D-glucanase from B. licheniformis KIBGE-IB2 for various industrial applications.
