Abstract
The effect of the introduction of a synthetic bypass, providing 2-ketoglutarate to succinate conversion via the intermediate succinate semialdehyde formation, on aerobic biosynthesis of succinic acid from glucose through the oxidative branch of the tricarboxylic acid cycle in recombinant Escherichia coli strains has been studied. The strain lacking the key pathways of acetic, lactic acid and ethanol formation from pyruvate and acetyl-CoA and possessing modified system of glucose transport and phosphorylation was used as a chassis for the construction of the target recombinants. The operation of the glyoxylate shunt in the strains was precluded resulting from the deletion of the aceA, aceB, and glcB genes encoding isocitrate lyase and malate synthases A and G. The constitutive activity of isocitrate dehydrogenase was ensured due to deletion of isocitrate dehydrogenase kinase/phosphatase gene, aceK. Upon further inactivation of succinate dehydrogenase, the corresponding strain synthesized succinic acid from glucose with a molar yield of 24.9%. Activation of the synthetic bypass by the induced expression of Mycobacterium tuberculosis 2-ketoglutarate decarboxylase gene notably increased the yield of succinic acid. Functional activity of the synthetic bypass in the strain with the inactivated glyoxylate shunt and opened tricarboxylic acid cycle led to 2.7-fold increase in succinate yield from glucose. As the result, the substrate to the target product conversion reached 67.2%. The respective approach could be useful for the construction of the efficient microbial succinic acid producers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.