Abstract
Our previous work has shown that L-isoleucine production in Corynebacterium glutamicum IWJ001 could be increased by overexpressing ilvA1 encoding a feedback-resistant threonine dehydratase, ilvBN1 encoding a feedback-resistant acetohydroxy acid synthase, lrp encoding the global regulator Lrp, brnFE encoding the two-component export system BrnFE, or ppnk1 encoding NAD kinase. The main purpose of this study is to further increase the L-isoleucine production in C. glutamicum IWJ001 by overexpressing the above genes in various combinations. Several C. glutamicum strains IWJ001/pDXW-8-ppnk1-lrp-brnFE, IWJ001/pDXW-8-ilvBN1-ilvA1-lrp-brnFE, IWJ001/pDXW-8-ilvBN1-ilvA1-ppnk1, and IWJ001/pDXW-8-ppnk1-ilvBN1-ilvA1-lrp-brnFE were constructed, and L-isoleucine production and activities of several key enzymes in these strains were analyzed. Compared with the control strain IWJ001/pDXW-8, L-isoleucine production increased in all of the four strains. IWJ001/pDXW-8-ilvBN1-ilvA1-ppnk1 showed the highest L-isoleucine production and produced 32.3 g/L L-isoleucine in 72 h fed batch fermentation. The results indicate that L-isoleucine production in C. glutamicum could be increased by enhancing the carbon flux and NADPH supply in the biosynthetic pathway.
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.