Immobilization of alpha- Amylase on Mesoporous Silica KIT-6 and Palm Wood Chips for Starch Hydrolysis

Abstract

?-Amylase was immobilized on highly ordered mesoporous silica KIT-6 and palm wood chips (PWC) by physical adsorption. The activity of the immobilized enzyme for starch hydrolysis was investigated at different solution pH and enzyme concentration for both supports. The thermal stability of the immobilized enzyme was also investigated for both supports. The result indicates that the maximum activity, in terms of glucose concentration, for both supports was observed close to the isoelectric point (PI = 7.00) of the enzyme. Activity increased with increasing concentration of the enzyme solution for both supports. The glucose to support ratio of 48 was obtained for KIT-6 compared to a value of 0.6 obtained for PWC. KIT-6 shows superior thermal stability. The exceptional performance of KIT-6 relative to PWC can be ascribed to its high adsorptive capacity as well as its excellent mass transfer characteristics arising from its very high surface area, large pore diameter and highly ordered pores.

Keywords: Mesoporous silica, KIT-6, Palm wood chips, Enzyme immobilization, ?-amylase, Starch hydrolysis