PENINGKATAN STABILITAS ENZIM AMILASE MELALUI AMOBILISASI PADA POLIMER KITOSAN

Abstract

In this study, the amylase enzym was immobilized on chitosan as a supporting agent with the aim enhance the stability of the enzyme.  The activity of immobilized enzyme was determined in terms of glucose and protein produced.  The amount of glucose was determined using dinitro salysilic (DNS) as a reagent, and the amount of protein using the method of Lowry.  The results obtained revealed that  chitosan possess good capacity to adsorb the enzyme, with 79.34% of the enzyme was immobilized. The activity measurements demonstrated that for the free enzyme the optimum activity was achieved at pH 7.0 with temperature of 55°C, and incubation time of 70 minutes.  For immobilized enzyme, the highest activity was achieved at pH 7.5 with temperature of 110°C, and incubation time of  80 minutes.  At room temperature storage, the activity of free enzyme was found to decrease 79.29% from the original activity after four days, while the activity of the immobilized enzyme, only 10.42% decrease was observed.   Thre immobilized enzyme was found to retain 50% activity after the third reusage, and 36.71% after the fifteenth reusage.

Keywords: Immobilization, enzym actifity, chitosan, enzym stability, adsorption..