文献类型：期刊文献

英文题名：Efficient production of (R)-(-)-mandelic acid with highly substrate/product tolerant and enantioselective nitrilase of recombinant Alcaligenes sp.

作者：Zhang, Zhi-Jun[1];Xu, Jian-He[1];He, Yu-Cai[1];Ouyang, Li-Ming[1];Liu, You-Yan[2];Imanaka, Tadayuki[1,3]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biocatalysis & Bioproc, Shanghai 200237, Peoples R China;[2]Guangxi Univ, Coll Chem & Chem Engn, Nanning 530004, Guangxi, Peoples R China;[3]Ritsumeikan Univ, Coll Life Sci, Dept Biotechnol, Shiga 5258577, Japan

年份：2010

卷号：45

期号：6

起止页码：887

外文期刊名：PROCESS BIOCHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000277908100010)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Nos. 20672037, 20773038 & 20902023), Ministry of Science and Technology, PR China (Nos. 2009ZX09501-016 & 2009CB724706), China National Special Fund for State Key Laboratory of Bioreactor Engineering (No. 2060204) and Shanghai Municipal Fund for Natural Science (No. 07ZR14030).

语种：英文

外文关键词：Alcaligenes sp.; Nitrilase; Enantioselective; Highly substrate/product tolerable; (R)-(-)-Mandelic acid; Fed-batch reaction

摘要：For efficient production of (R)-(-)-mandelic acid, a nitrilase gene from Alcaligenes sp. ECU0401 was cloned and overexpressed in Escherichia coli. After simple optimization of the culture conditions, the biocatalyst production was greatly increased from 500 to 7000 U/l. The recombinant E. coli whole cells showed strong tolerance against a high substrate concentration of up to 200 mM, and the concentration of (R)-(-)-mandelic acid after only 411 of transformation reached 197 mM with an enantiomeric excess (ee(p)) of 99%. In a fed-batch reaction with 600 mM mandelonitrile as the substrate, the cumulative production of (R)-(-)-mandelic acid after 17.5 h of conversion reached 520 mM. The recombinant E. coli cells could also be repeatedly used in the biotransformation, retaining 40% of the initial activity after 10 batches of reaction. The highly substrate/product tolerable and enantioselective nature of this recombinant nitrilase suggests that it is of great potential for the practical production of optically pure (R)-(-)-mandelic acid. (C) 2010 Elsevier Ltd. All rights reserved.