|
KMID : 1094720140190010132
|
|
Biotechnology and Bioprocess Engineering
2014 Volume.19 No. 1 p.132 ~ p.142
|
|
|
Enhancing the carbon flux and NADPH supply to increase L-isoleucine production in Corynebacterium glutamicum
|
|
Yin Lianghong
Zhao Jianxun
Chen Cheng
Hu Xiaoqing
Wang Xiaoyuan
|
|
|
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.
|
|
|
KEYWORD
|
|
|
Corynebacterium glutamicum, L-isoleucine, ilvBN, ilvA, ppnk, lrp, brnFE, NADPH
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
 
|
|