Enhanced activity of yqhD oxidoreductase in synthesis of 1,3-propanediol by error-prone PCR
yqhD oxidoreductase was determined to be an NADP-dependent dehydrogenase,and was more active toward 3-HPA when compared to 1,3-propanediol oxidoreductase.To further improve enzyme activity towards 3-hydroxypropionaldehyde (3-HPA),error-prone PCR was implemented to mutant yqhD gene.Two mutants,D99QN147H and Q202A with increased catalytic and affinity efficiency,were obtained after one round of error-prone polymerase chain reaction.And the catalytic efficiency of the mutant D99QN147H was up to 4-fold greater than the wild enzyme (0.0375 min-1 mM-1 vs.0.0078 min-1 mM-1).The recombined strain containing pET28yqhD D99QNI47H yielded 28 g L-1 of 1,3-propanediol in the fed-batch LB cultures (1 L volume) with an initial 3-HPA concentration of 40 g L-1,which was higher than the 21 and 17 g L-1 of 1,3-propanediol from the mutant Q202A and the wild-type,respectively.Except for propionaldehyde,the optimal mutant D99QN147H also exhibited higher activity on a range of substituted aldehydes than the wild-type.
作 者： Hongmei Li Jia Chen Yinghua Li 作者单位： Hongmei Li,Jia Chen(Institute of Food Science and Biological Technology, University of Shanghai for Science and Technology, Shanghai 200093, China)Yinghua Li(Institute of Pharmaceutical Engineering, Zhejiang University, Hangzhou 310027, China)
刊 名： 自然科学进展（英文版） SCI 英文刊名： PROGRESS IN NATURAL SCIENCE 年，卷(期)： 2008 18(12) 分类号： N1 关键词： yqhD oxidoreductase Error-prone PCR Catalytic efficiency 1,3-Propanediol