title: [Immobilization of lipase by chemical modification of chitosan].
abstract: Lipase (EC3.1.1.3) from Candida sp. 99-125 was immobilized on chitosan by chemical covalence. Lipase was first immobilized to chitosan beads by activating its hydroxyl groups with carbodiimide followed by cross-linking more lipase to the amino groups with glutaraldehyde. In this article, different factors that influenced the immobilization were investigated, and the optimum conditions were ascertained. Comparative studies of organic solvent and thermal stability between free lipase and immobilized lipase were conducted. Immobilization enhanced the lipase stability against changes of temperature and organic solvent. Immobilization lipase can be reused in the synthesis system of palmitate hexadecyl. Operational stability tests indicated that the immobilized lipase occurs after 16 consecutive batches, the conversion rate remained 85%. Such results revealed good potential for recycling under esterification system.
authors.affiliation: College of Life Science and Technology, Beijing University of Chemical and Technology, Beijing 100029, China.
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Hu
authors.forename: Tian-Wei
authors.initials: TW
authors.lastname: Tan
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
mesh_terms: D002175:Candida / Q000201:enzymology*; D002234:Carbodiimides / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D008049:Lipase / Q000378:metabolism*; D010168:Palmitates / Q000737:chemistry