Reference

Asymmetric reduction of ethyl 4-chloroacetoacetate to R-(+)-4-chloro-3-hydroxybutyrate by recombinant Escherichia coli strains

All Rights Reserved. Asymmetric reduction of ethyl 4-chloroacetoacetate to R-(+)-4-chloro-3-hydroxybutyrate by recombinant Escherichia coli strains. Jing, Li; Lin, Jianping; Xu, Zhinan; Tan, Tianwei; Cen, Peilin (Institute of Material and Chemical Engineering, Zhejiang University, Hangzhou 310027, Peop. Rep. China). Huaxue Fanying Gongcheng Yu Gongyi, 22(4), 350-355 (Chinese) 2006 Huaxue Fanying Gongcheng Yu Gongyi Bianjibu. CODEN: HFGGEU. ISSN: 1001-7631. DOCUMENT TYPE: Journal CA Section: 16 (Fermentation and Bioindustrial Chemistry) Section cross-reference(s): 3 NADP-dependent aldehyde reductase gene ALR and glucose-6-phosphate dehydrogenase gene gdh223 were cloned from Sporobolomyces salmonicolor and Bacillus megaterium ZJU0310 resp. in Escherichia coli. The recombinant E. coli M15 (pQE30-ALRgdh223) strain was and optimized by investigating the effects of the time of adding isopropylthiogalactoside (IPTG), IPTG concn. and temp. on enzyme activity. Expt. results showed that optimized conditions were IPTG concn. 0.4 mmol/L, 32 °C, 8 h. Under optimized conditions, 5.27 U/mg-protein of enzyme activity was obtained after 8 h cultivation. The asym. redn. of Et 4-chloroacetoacetate to R-(+)-4-chloro-3-hydroxybutyrate was carried out and it was found that the recombinant Escherichia Coli strain could regenerate coenzymes and increase ee. When reaction temp.In this experiment, several chemicals are used like 367-93-1 and 90866-33-4 was increased, product yield was increased, but over 32 °C, product yield was decreased. The reactant had an inhibiting effect on the reaction. The inhibition could be weakened and product yield could be increased by a fed-batch approach. .

High-level expression of recombinant glucose dehydrogenase and its application in NADPH regeneration

All Rights Reserved. High-level expression of recombinant glucose dehydrogenase and its application in NADPH regeneration.Several substances are used for example 90866-33-4 and 53-57-6 which are their cas registry numbers. Xu, Zhinan; Jing, Keju; Liu, Ying; Cen, Peilin (Department of Chemical Engineering and Bioengineering, Institute of Bioengineering, Zhejiang University, Hangzhou 310027, Peop. Rep. China). Journal of Industrial Microbiology & Biotechnology, 34(1), 83-90 (English) 2007 Springer. CODEN: JIMBFL. ISSN: 1367-5435. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) Two glucose dehydrogenase (E.C. 1.1.1.47) genes, gdh223 and gdh151, were cloned from Bacillus megaterium AS1.223 and AS1.151, and were inserted into pQE30 to construct the expression vectors, pQE30-gdh223 and pQE30-gdh151, resp. The transformant Escherichia coli M15 with pQE30-gdh223 gave a much higher glucose dehydrogenase activity than that with the plasmid pQE30-gdh151. Thus it was used to optimize the expression of glucose dehydrogenase. An approx. tenfold increase in GDH activity was achieved by the optimization of culture and induction conditions, and the highest productivity of glucose dehydrogenase (58.7 U/mL) was attained. The recombinant glucose dehydrogenase produced by E. coli M15 (pQE30-gdh223) was then used to regenerate NADPH. NADPH was efficiently regenerated in vivo and in vitro when 0.1 M glucose was supplemented concomitantly in the reaction system. Finally, this coenzyme-regenerating system was coupled with a NADPH-dependent bioredn. for efficient synthesis of Et (R)-4-chloro-3-hydroxybutanoate from Et 4-chloro-3-oxobutanoate. .