title: Production of S-acetoin from diacetyl by Escherichia coli transformant cells that express the diacetyl reductase gene of Paenibacillus polymyxa ZJ-9.
abstract: S-acetoin (S-AC) is an important four-carbon chiral compound that has unique industrial applications in the asymmetric synthesis of valuable chiral specialty chemicals. However, previous studies showed that the usually low yield and optical purity of S-AC as well as the very high substrate cost have hindered the application of this compound. In the current work, a gene encoding diacetyl reductase (DAR) from a Paenibacillus polymyxa strain ZJ-9 was cloned and expressed in Escherichia coli. Whole cells of the recombinant E. coli were used to produce S-AC from diacetyl (DA). Under optimal conditions, S-AC with high optical purity (purity >99·9%) was obtained with a yield of 13·5 ± 0·24 and 39·4 ± 0·38 g l(-1) under batch and fed-batch culture conditions, respectively. This process featured the biotransformation of DA into S-AC using whole cells of engineered E. coli. The result is a considerable increase in the yield and optical purity of S-AC, which in turn facilitated the practical application of the compound.
  
  
  CONCLUSIONS
  This study demonstrated a highly efficient new method to produce S-acetoin with higher than 99·9% optical purity from diacetyl using whole cells of engineered Escherichia coli. It will therefore decrease the production cost of S-acetoin and highlight its application in asymmetric synthesis of highly valuable chiral compounds.
authors.affiliation: Schol of Chemical and Biological Engineering, Yancheng Institute of Technology, Yancheng, China.
authors.forename: J
authors.initials: J
authors.lastname: Gao
authors.forename: Y Y
authors.initials: YY
authors.lastname: Xu
authors.forename: F W
authors.initials: FW
authors.lastname: Li
authors.forename: G
authors.initials: G
authors.lastname: Ding
mesh_terms: D000093:Acetoin / Q000378:metabolism*; D000094:Acetoin Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003931:Diacetyl / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005818:Genetic Engineering; D056507:Paenibacillus / Q000201:enzymology* / Q000235:genetics; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; D000093:Acetoin; D000094:Acetoin Dehydrogenase; D003931:Diacetyl
keywords: S-acetoin; biotransformation; diacetyl; diacetyl reductase; transformant cells