This title appears in the Scientific Report :
2011
Please use the identifier:
http://dx.doi.org/10.1128/AEM.00575-11 in citations.
Comparative 13C-metabolic flux analysis of pyruvate dehydrogenase complex-deficient L-valine-producing Corynebacterium glutamicum
Comparative 13C-metabolic flux analysis of pyruvate dehydrogenase complex-deficient L-valine-producing Corynebacterium glutamicum
L-Valine can be formed successfully using C. glutamicum strains missing an active pyruvate dehydrogenase enzyme complex (PDHC). Wild-type C. glutamicum and four PDHC-deficient strains were compared by (13)C metabolic flux analysis, especially focusing on the split ratio between glycolysis and the pe...
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Personal Name(s): | Bartek, T. |
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Blombach, B. / Lang, S. / Eikmanns, B.J. / Wiechert, W. / Oldiges, M. / Nöh, K. / Noack, S. | |
Contributing Institute: |
Biotechnologie 2; IBT-2 |
Published in: | Applied and environmental microbiology, 77 (2011) S. 6644 - 6652 |
Imprint: |
Washington, DC [u.a.]
Soc.
2011
|
Physical Description: |
6644 - 6652 |
PubMed ID: |
21784914 |
DOI: |
10.1128/AEM.00575-11 |
Document Type: |
Journal Article |
Research Program: |
Biotechnologie |
Series Title: |
Applied and Environmental Microbiology
77 |
Subject (ZB): | |
Publikationsportal JuSER |
L-Valine can be formed successfully using C. glutamicum strains missing an active pyruvate dehydrogenase enzyme complex (PDHC). Wild-type C. glutamicum and four PDHC-deficient strains were compared by (13)C metabolic flux analysis, especially focusing on the split ratio between glycolysis and the pentose phosphate pathway (PPP). Compared to the wild type, showing a carbon flux of 69% ± 14% through the PPP, a strong increase in the PPP flux was observed in PDHC-deficient strains with a maximum of 113% ± 22%. The shift in the split ratio can be explained by an increased demand of NADPH for l-valine formation. In accordance, the introduction of the Escherichia coli transhydrogenase PntAB, catalyzing the reversible conversion of NADH to NADPH, into an L-valine-producing C. glutamicum strain caused the PPP flux to decrease to 57% ± 6%, which is below the wild-type split ratio. Hence, transhydrogenase activity offers an alternative perspective for sufficient NADPH supply, which is relevant for most amino acid production systems. Moreover, as demonstrated for L-valine, this bypass leads to a significant increase of product yield due to a concurrent reduction in carbon dioxide formation via the PPP. |