文献类型：期刊文献

英文题名：Efficient production of (R)-(-)-mandelic acid using glutaraldehyde cross-linked Escherichia coli cells expressing Alcaligenes sp nitrilase

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

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

年份：2014

卷号：37

期号：7

起止页码：1241

外文期刊名：BIOPROCESS AND BIOSYSTEMS ENGINEERING

收录：;EI(收录号：20142717892378);WOS:【SCI-EXPANDED(收录号:WOS:000338237700003)】；

基金：This work was financially supported by the National Science Foundation of China (Nos. 21276082 & 31200050), Ministry of Science and Technology, P. R. China (Nos. 2011CB710800, 2011AA02A210 & 2012AA022201), Shanghai Commission of Science and Technology (No. 11431921600) and the Fundamental Research Funds for the Central Universities (No. 222201314016).

语种：英文

外文关键词：Immobilized cells; Alcaligenes sp nitrilase; Glutaraldehyde cross-linking; Enantioselective hydrolysis; (R)-(-)-Mandelic acid

摘要：Recombinant Escherichia coli cells expressing Alcaligenes sp. nitrilase were simply immobilized by direct cross-linking using glutaraldehyde. About 85 % of the total nitrilase activity was recovered under the optimal cross-linking conditions. The thermal stabilities of the cross-linked cells measured at 30, 40 and 50 A degrees C were 4.5-, 5.3-, and 5.1-fold those of the free cells, respectively. The concentration of (R)-(-)-mandelic acid reached 280 mM after merely 2 h transformation with the immobilized cells using 300 mM mandelonitrile as substrate, affording an extremely high productivity of 510.7 g L-1 d(-1). In addition, operational stability of the immobilized cells was obviously superior to that of free cells, without significant activity loss after 15 cycles of batch reactions or 8 cycles of repeated fed-batch reactions. Therefore, the easy preparation and robust characteristics of the immobilized biocatalyst make it a very promising biocatalyst for high-performance and low-cost production of optically pure (R)-(-)-mandelic acid.