A Novel Microbacterium sp. for Asymmetric Reduction of Simple Aromatic Ketone and Its Key Reductase
Li Luo1, Zhong-Hua Yang1*, Rong Zeng2*, Wei Zhou1, Yan Zhao1, Geng-Hua Chen1 and Hao Huang1
1College of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081, PR China
2College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China
Article history:
Received August 8, 2012
Accepted November 6, 2012
Key words:
asymmetric reduction, Microbacterium sp., aromatic ketone reductase, acetophenone
Summary:
A novel strain, Microbacterium sp., which can be used as a catalyst in the asymmetric reduction of simple aromatic ketones to produce chiral aromatic alcohols, was isolated from soil by microbial screening. Using acetophenone as a model substrate for asymmetric reduction, 82 % reaction yield with more than 99 % enantiomeric excess of (R)-1-phenylethanol were achieved under the optimal conditions. Furthermore, the key reductase responsible for the asymmetric reduction was purified from the newly isolated Microbacterium sp. through (NH4)2SO4 fractional precipitation, anion exchange chromatography and gel filtration chromatography. The purified reductase is a NADH-dependent aromatic ketone reductase. Gel filtration chromatography and SDS-PAGE results reveal that it is a homodimer with two 28-kDa subunits. The enzymatic properties of the reductase indicate that it is a highly efficient catalyst for the asymmetric reduction of simple aromatic ketone.
*Corresponding author: 
++86 27 8656 3448
++86 27 6392 7637