Corynebacterium glutamicum was metabolically engineered for the production of glutaric acid, a C5 dicarboxylic acid that can be used as platform building block chemical for nylons and plasticizers. C. glutamicum gabT and gabD genes and Pseudomonas putida davT and davD genes encoding 5-aminovalerate transaminase and glutarate semialdehyde dehydrogenase, respectively, were examined in C. glutamicum for the construction of a glutaric acid biosynthesis pathway along with P. putida davB and davA genes encoding lysine 2-monooxygenase and delta-aminovaleramidase, respectively. The glutaric acid biosynthesis pathway constructed in recombinant C. glutamicum was engineered by examining strong synthetic promoters PH30 and PH36, C. glutamicum codon-optimized davTDBA genes, and modification of davB gene with an N-terminal His6-tag to improve the production of glutaric acid. It was found that use of N-terminal His6-tagged DavB was most suitable for the production of glutaric acid from glucose. Fed-batch fermentation using the final engineered C. glutamicum H30_GAHis strain, expressing davTDA genes along with davB fused with His6-tag at N-terminus could produce 24.5 g/L of glutaric acid with low accumulation of L-lysine (1.7 g/L), wherein 5-AVA accumulation was not observed during fermentation.
Bibliographical noteFunding Information:
This work was supported by the Mid-career Researcher Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT (MSIT) ( NRF-2016R1A2B4008707 ), the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries from MSIT through the NRF of Korea ( NRF-2015M1A2A2035810 ), the Bio & Medical Technology Development Program MSIT through the NRF of Korea ( NRF-2018M3A9H3020459 ) and the Lignin Biorefinery from MSIT through the NRF of Korea ( NRF-2017M1A2A2087634 ).
© 2018 International Metabolic Engineering Society
- Codon optimization
- Corynebacterium glutamicum
- Fed-batch fermentation
- Glutaric acid