Production of <Emphasis Type="Italic">R</Emphasis>-Mandelic Acid Using Nitrilase from Recombinant <Emphasis Type="Italic">E. coli</Emphasis> Cells Immobilized with Tris(Hydroxymethyl)Phosphine |
| |
Authors: | Xin-Hong Zhang Zhi-Qiang Liu Ya-Ping Xue Yuan-Shan Wang Bo Yang Yu-Guo Zheng |
| |
Institution: | 1.Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering,Zhejiang University of Technology,Hangzhou,P. R. China |
| |
Abstract: | Recombinant Escherichia coli cells harboring nitrilase from Alcaligenes faecalis were immobilized using tris(hydroxymethyl)phosphine (THP) as the coupling agent. The optimal pH and temperature of the THP-immobilized cells were determined at pH 8.0 and 55 °C. The half-lives of THP-immobilized cells measured at 35, 40, and 50 °C were 1800, 965, and 163 h, respectively. The concentration of R-mandelic acid (R-MA) reached 358 mM after merely 1-h conversion by the immobilized cells with 500 mM R,S-mandelonitrile (R,S-MN), affording the highest productivity of 1307 g L?1 day?1 and the space-time productivity of 143.2 mmol L?1 h?1 g?1. The immobilized cells with granular shape were successfully recycled for 60 batches using 100 mM R,S-MN as substrate at 40 °C with 64% of relative activity, suggesting that the immobilized E. coli cells obtained in this study are promising for the production of R-MA. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|