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

Abstract

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 61gL(-1) (R,R)-2,3-BDO in a fed-batch fermentation. On the other hand, meso-2,3-BDO was produced 1.4gL(-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.

• Authors: Soojin Lee, Borim Kim, Jeongmo Yang, Daun Jeong, Soohyun Park, Jinwon Lee
• Journal: Journal of biotechnology (J Biotechnol) Vol. 209 Pg. 7-13 (Sep 10 2015) ISSN: 1873-4863 [Electronic] Netherlands
• PMID: 26074000 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• Bacterial Proteins
• Butylene Glycols
• 2,3-butylene glycol

Topics

• Bacterial Proteins (genetics)
• Batch Cell Culture Techniques (methods)
• Butylene Glycols (metabolism)
• Gene Deletion
• Genetic Enhancement (methods)
• Klebsiella (genetics, metabolism)
• Metabolic Engineering (methods)