Immobilization of Candida antarctica lipase B on the surface of modified sol-gel matrix

Abstract

The use of modified sol-gel matrix to immobilize the enzyme Candida antartica lipase B (CALB) was investigated. Free hydroxyl groups on the matrix surface were exploited to covalently immobilize the enzyme. Based from the results, incorporating hydrophobic sol-gel precursor (ethyltrimethoxysilane) enhanced enzyme activity. An enzyme activity of 192.02 U/g beads with 80.88 % attachment was obtained. At alkaline pH, immobilization yield of enzyme increased. The attachment of enzyme on the surface of the matrix was confirmed by scanning electron microscope images. Covalently immobilized CALB on sol-gel supports has higher thermal stability with 2.7 times higher half-life compared to soluble enzymes at 60 A degrees C. This enzyme immobilization system retains the enzyme residual activity even for repetitive use. Hence, the immobilization approach developed recommends its further application.