文献类型：期刊文献

英文题名：Immobilization of Bacillus subtilis esterase by simple cross-linking for enzymatic resolution of DL-menthyl acetate

作者：Zheng, Gao-Wei[1];Yu, Hui-Lei[1];Li, Chun-Xiu[1];Pan, Jiang[1];Xu, Jian-He[1]

机构：[1]E China Univ Sci & Technol, Lab Biocatalysis & Bioproc, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2011

卷号：70

期号：3-4

起止页码：138

外文期刊名：JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000290776600009)】；

基金：This work was financially supported by the National Natural Science Foundation of China (nos. 20902023 & 31071604), Ministry of Science and Technology, PR China (nos. 2009ZX09501-016 & 2011CB710800), China National Special Fund for State Key Laboratory of Bioreactor Engineering (no. 2060204) and Shanghai Leading Academic Discipline Project (no. B505).

语种：英文

外文关键词：Bacillus subtilis esterase; Cross-linked enzyme aggregates; Hydrolysis; Immobilization; L-Menthol

摘要：A recombinant esterase (EC 3.1.1.1) cloned from Bacillus subtilis 0554 (BSE) was carrier-freely immobilized with the method of cross-linked enzyme aggregates. The conditions for preparing the cross-linked aggregates of BSE (CLA-BSE) were optimized, including the type and concentration of precipitants, and the concentration of cross-linker, and a simple and efficient procedure for preparing CLA-BSE was developed, consisting of a precipitation step with 0.5 g mL(-1) (NH(4))(2)SO(4) and a cross-linking step with 60 mM glutaraldehyde for a period of 3 h as the cross-linking time. As a result, about 70% of the initial free BSE activity was incorporated into the CLA-BSE. The thermal stabilities of the immobilized enzyme at 30 degrees C and 50 degrees C were >360 and 14 times those of free BSE, respectively. More importantly, the operational stability of CLA-BSE was also considerably improved. In the kinetic resolution of DL-menthyl acetate to produce L-menthol with CLA-BSE gave ee(p) >94% at conversion of >40% and the CLA-BSE could be reused for 10 times with only about 8% reduction in activity. Therefore, the new biocatalyst immobilized through the methodology of CLEAs could significantly decrease the manufacturing cost of L-menthol and would be more beneficial for its practical applications. (C) 2011 Elsevier B.V. All rights reserved.