A non-pathogenic and optically high concentrated (R,R)-2,3-butanediol biosynthesizing Klebsiella strain

作者：Lee Soojin; Kim Borim; Yang Jeongmo; Jeong Daun; Park Soohyun; Lee Jinwon^*

来源：Journal of Biotechnology, 2015, 209: 7-13.

DOI：10.1016/j.jbiotec.2015.06.385

• 2,3-Butanediol stereoisomers
• (R,R)-2,3-butanediol

The objective of this work was to construct a non-pathogenic Klebsiella pneumonia strain that can produce optically high concentrated (R,R)-2,3-BDO. A K. pneumonia mutant lacking the pathogenic factor was used as the host strain. In order to construct a K. pneumonia strain that would biosynthesize high concentrated (R,R)-2,3-BDO, gene deletion and over-expression methods were combined; firstly, the 2,3-BDO dehydrogenase (budC) gene was deleted to re-direct utilization of the carbon source to (R,R)-2,3-BDO biosynthesis; secondly, the two glycerol dehydrogenase (GDH) enzymes in K. pneumonia (DhaD and GldA) were over-expressed to maximize (R,R)-2,3-BDO biosynthesis; and thirdly, the lactate dehydrogenase (ldhA) gene was deleted to minimize the accumulation of lactate. SGSB112, a non-pathogenic strain of K. pneumonia that can produce optically high concentrated (R, R)-2,3-BDO, was constructed as above. Approximately 36% of the carbon source was converted to (R,R)-2,3-BDO by SGSB112, achieving a production of 61 g L-1 (R,R)-2,3-BDO in a fed-batch fermentation. On the other hand, meso-2,3-BDO was produced 1.4 g L-1 and (S,S)-2,3-BDO was not detected. This study provides an insight into 2,3-BDO biosynthesis in K. pneumonia and demonstrates the achievement of high-yield production of optically high concentrated (R,R)-2,3-BDO through constructing a strain by genetic modification and metabolic engineering.

• 出版日期2015-9-10