BioChem - DOS

Effective asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate to ethyl (R)-4-chloro-3-hydroxybutanoate by recombinant E. coli CCZU-A13 in [Bmim]PF6-hydrolyzate media

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

He, Yu-Cai; Tao, Zhi-Cheng; Di, Jun-Hua; Chen, Liang; Zhang, Lin-Bing; Zhang, Dan-Ping; Chong, Gang-Gang; Liu, Feng; Ding, Yun; Jiang, Chun-Xia; Ma, Cui-Luan

<P><B>Abstract</B></P> <P>It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3wt%)-soaking rice straw at 30&deg;C was used to form [Bmim]PF<SUB>6</SUB>-hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (<I>R</I>)-4-chloro-3-hydroxybutanoate [(<I>R</I>)-CHBE] (>99% <I>e.e.</I>) with recombinant <I>E. coli</I> CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20mM) was employed to improve the reductase activity. Moreover, Hp-&beta;-cyclodextrin (0.01mol Hp-&beta;-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of (<I>R</I>)-CHBE from COBE by <I>E. coli</I> CCZU-A13 whole-cells. The yield of (<I>R</I>)-CHBE (>99% <I>e.e.</I>) from 800mM COBE was obtained at 100% in the [Bmim]PF<SUB>6</SUB>-hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20mM) and Hp-&beta;-CD (8mM). In conclusion, an effective strategy for the biosynthesis of (<I>R</I>)-CHBE was successfully demonstrated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrolyzates promoted initial reaction rate and intracellular NADH content. </LI> <LI> Emulsifier OP-10 (20mM) increased the initial reaction rate of whole cells. </LI> <LI> Hp-&beta;-cyclodextrin (0.010mol Hp-&beta;-CD/mol COBE) increased the initial reaction rate. </LI> <LI> Effective biosynthesis of (<I>R</I>)-CHBE (800mM) was in [Bmim]PF<SUB>6</SUB>-hydrolyzate media. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2016

Elsevier

0960-8524

214

pp.411-418

10.1016/j.biortech.2016.04.134

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART75722559

Rice straw; Dilute NaOH pretreatment; Ethyl 4-chloro-3-oxobutanoate; Ethyl (R)-4-chloro-3-hydroxybutanoate; E. coli CCZU-A13