Metabolic engineering of Corynebacterium glutamicum for efficient production of optically pure (2R,3R)-2,3-butanediol
Journal article, 2022
Results: In this study, a (3R)-acetoin overproducing C. glutamicum strain, CGS9, was engineered to produce optically pure (2R,3R)-2,3-butanediol efficiently. Firstly, the gene bdhA from B. subtilis 168 was integrated into strain CGS9 and its expression level was further enhanced by using a strong promoter Psod and ribosome binding site (RBS) with high translation initiation rate, and the (2R,3R)-2,3-butanediol titer of the resulting strain was increased by 33.9%. Then the transhydrogenase gene udhA from E. coli was expressed to provide more NADH for 2,3-butanediol synthesis, which reduced the accumulation of the main byproduct acetoin by 57.2%. Next, a mutant atpG was integrated into strain CGK3, which increased the glucose consumption rate by 10.5% and the 2,3-butanediol productivity by 10.9% in shake-flask fermentation. Through fermentation engineering, the most promising strain CGK4 produced a titer of 144.9 g/L (2R,3R)-2,3-butanediol with a yield of 0.429 g/g glucose and a productivity of 1.10 g/L/h in fed-batch fermentation. The optical purity of the resulting (2R,3R)-2,3-butanediol surpassed 98%.
Conclusions: To the best of our knowledge, this is the highest titer of optically pure (2R,3R)-2,3-butanediol achieved by GRAS strains, and the result has demonstrated that C. glutamicum is a competitive candidate for (2R,3R)-2,3-butanediol production.
Microbial fermentation
Metabolic engineering
Corynebacterium glutamicum
(2R,3R)-2,3-butanediol
Author
Mengyun Kou
Tianjin University
Zhenzhen Cui
Tianjin University
Jing Fu
Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology
Wei Dai
Tianjin University
Zhiwen Wang
Tianjin University
Tao Chen
Tianjin University
Microbial Cell Factories
14752859 (eISSN)
Vol. 21 1 150Subject Categories
Microbiology
Microbiology in the medical area
Other Industrial Biotechnology
DOI
10.1186/s12934-022-01875-5
PubMed
35879766