Overexpression of Corynebacterium glutamicum NAD kinase improves L-isoleucine biosynthesis / 生物工程学报
Chinese Journal of Biotechnology
;
(12): 1038-1047, 2012.
Article
Dans Chinois
| WPRIM
| ID: wpr-342418
ABSTRACT
NAD kinase catalyzes the phosphorylation of coenzyme I [NAD(H)] to form coenzyme II [NADP(H)], and NADPH is an important cofactor in L-isoleucine biosynthesis. In order to improve NADPH supply, ppnK, the gene encoding NAD kinase in Corynebacterium glutamicum was cloned and separately expressed in an L-isoleucine synthetic strain, Brevibacterium lactofermentum JHI3-156, by an inducible expression vector pDXW-8 and a constitutive expression vector pDXW-9. Compared with the control strain JHI3-156/pDXW-8, NAD kinase activity of the inducible ppnK-expressing strain JHI3-156/pDXW-8-ppnK was increased by 83.5%. NADP(H)/NAD(H) ratio was also increased by 63.8%. L-isoleucine biosynthesis was improved by 82.9%. Compared with the control strain JHI3-156/pDXW-9, NAD kinase activity of the constitutive ppnK-expressing strain JHI3-156/pDXW-9-ppnK was increased by 220%. NADP(H)/ NAD(H) ratio and NADPH concentration were increased by 134% and 21.7%, respectively. L-isoleucine biosynthesis was increased by 41.7%. These results demonstrate that NAD kinase can improve the coenzyme II supply and L-isoleucine biosynthesis, which would also be useful for biosynthesis of other amino acids.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Protéines recombinantes
/
Brevibacterium
/
Clonage moléculaire
/
Phosphotransferases (Alcohol Group Acceptor)
/
Corynebacterium glutamicum
/
Génie métabolique
/
Génétique
/
Isoleucine
/
Métabolisme
/
NAD
langue:
Chinois
Texte intégral:
Chinese Journal of Biotechnology
Année:
2012
Type:
Article
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