Immobilization of α-amylase from locale bacteria isolate Bacillus subtilis ITBCCB148 with carboxymethyl cellulose (CM-Cellulose)

Abstract

This paper describes the stability increase of α-amylase obtained from Bacillus subtilis ITBCCB 148 by immobilization process using carboxymethyl cellulose (CM-Cellulose) as the immobile matrix. To achieve this aim the enzyme was purified by the following steps: fractionation with ammonium sulphate, dialysis, ion exchange column chromatography with CM-cellulose and molecule filtration column chromatography with Sephadex G-100. The purified enzyme was then immobilized with CM-Cellulose. The result showed that the immobilization with CM-cellulose on α-amylase obtained from B. subtilis has successfully increased the thermal stability of the native enzyme. The thermal stabilities of the modified enzyme were increased 3.67 times compared to the native enzyme. The decrease of ki value, the increase of half-life and ΔGi values showed that the modified enzymes were more stable than the native enzyme.