Immobilization of a - amylase from locale bacteria isolate Bacillus subtilis ITBCCB148 with diethylaminoethyl cellulose (DEAE-Cellulose)

YANDRI, TATI SUHARTATI and SUTOPO HADI

Department of Chemistry, Faculty of Mathematics and Natural Sciences University of Lampung, Bandar Lampung - 35145 (Indonesia)

Received on April 15, 2010 and accepted on May 26, 2010

ABSTRACT

The thermal stability increase of a-amylase obtained from locale bacteria isolate Bacillus subtilis ITBCCB148 was achieved by immobilization process using an ionic exchange matrix of DEAE-Cellulose. The result showed that the immobilized enzyme has an optimum temperature of 60°C; KM 14.8 mL substrate and Vmax 42.4 U/mL. The thermal stability storage temperature of 60°C, pH 9.0 and 60 minutes demonstrated the immobilized enzyme has residual activity of 28.1%; ki = 0.0224 min.-1; and DGi = 103.7 kJ mol-1. Although the immobilized enzyme’s thermal stability was only increased 1.5 times, at higher temperatures, it was much more stable than the native enzyme.

Keywords : a-amylase, immobilization, DEAE-Cellulose, B. subtilis ITBCCB148