(314c) A Facile Method to Prepare Chemically Crosslinked and Efficient Polyvinyl Alcohol/Chitosan Beads for Catalase Immobilization

Catalase (hydrogen peroxide oxidoreductase; EC.1.11.1.6) which can catalyze the decomposition of hydrogen peroxide to water and oxygen has been used in various industrial fields, such as in removal of hydrogen peroxide from food industry or textile industry, and in the analytical field as a component of hydrogen peroxide or glucose biosensor systems. However, catalase is suffering from deactivating in a short lifetime, and hard to reuse under practical reaction. To overcome these drawbacks, immobilization of catalase on insoluble supports has been performed as an effective way to implement efficient and continuous application of catalase. In the present study, PVA/chitosan material that forming a chemical bond between PVA and chitosan has been  researched in the application of immobilized enzyme. Firstly, some of the –OH on the PVA has been modified to –NH₂ with 3-aminopropyl triethoxysilane (APTES). And then chemical bond  between the –NH₂ on PVA and chitosan with the help of glutaraldehyde. FTIR and SEM have been used to character the hybrid material. Subsequently, catalase has been covalently immobilized onto the PVA/chitosan hybrid beads and its catalytic properties also have been studied by exploring its activity and stability. The results showed the activity of modified group was increased by 26% compared with control group. The optimal temperature of immobilized catalase was 45 ^◦C while the free enzyme was 25^◦C. This indicated that thermal stability of catalase has been enhanced. Moreover, this immobilized catalase retained over 90% of its original activity after using for 9 times. All these merits indicated that the immobilized catalase could have an efficient potential in practical application.