COMPARATIVE STUDY ON THE IMMOBILIZATION OF LIPASE ON CHITOSAN GELS MODIFIED BY DIFFERENT HYDROPHOBIC GROUPS

The hydrophobic surface modification of chitosan gels (CS) was carried out using the amidating reaction of amido groups on a gel surface with propionic acid, stearic acid, and benzoic acid, respectively, activated by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Lipase from Candida rugosa was immobilized by adsorption on the nascent CS, propionyl-modified gels (PCS), stearyl-modified gels (SCS), and benzoyl-modified gels (BCS), respectively. The adsorption capacity and activity of immobilized lipase were investigated. It was found that the surface modification improved the adsorption capacity of lipase, and the activity retention of immobilized lipase increased from 52.34% for CS to 57.17%, 78.26% and 69.22%, respectively, for PCS, SCS, and BCS.