Analysing overexpression of l-valine biosynthesis genes in pyruvate-dehydrogenase-deficient Corynebacterium glutamicum

  • Tobias Bartek
  • Enrico Zönnchen
  • Bianca Klein
  • Robert Gerstmeir
  • Pia Makus
  • Siegmund Lang
  • Marco Oldiges
Original Paper

DOI: 10.1007/s10295-009-0669-x

Cite this article as:
Bartek, T., Zönnchen, E., Klein, B. et al. J Ind Microbiol Biotechnol (2010) 37: 263. doi:10.1007/s10295-009-0669-x

Abstract

l-Valine biosynthesis was analysed by comparing different plasmids in pyruvate-dehydrogenase-deficient Corynebacterium glutamicum strains in order to achieve an optimal production strain. The plasmids contained different combinations of the genes ilvBNCDE encoding for the l-valine forming pathway. It was shown that overexpression of the ilvBN genes encoding acetolactate synthase is obligatory for efficient pyruvate conversion and to prevent l-alanine as a by-product. In contrast to earlier studies, overexpression of ilvE encoding transaminase B is favourable in pyruvate-dehydrogenase-negative strains. Its amplification enhanced l-valine formation and avoided extra- and intracellular accumulation of ketoisovalerate.

Keywords

Corynebacterium glutamicum l-Valine Pyruvate dehydrogenase Metabolome analysis Pathway analysis 

Copyright information

© Society for Industrial Microbiology 2009

Authors and Affiliations

  • Tobias Bartek
    • 1
    • 4
  • Enrico Zönnchen
    • 1
  • Bianca Klein
    • 1
  • Robert Gerstmeir
    • 2
  • Pia Makus
    • 1
  • Siegmund Lang
    • 3
  • Marco Oldiges
    • 1
  1. 1.Institute of Biotechnology 2JülichGermany
  2. 2.Evonik Degussa GmbHKünsebeckGermany
  3. 3.Institute for Biochemistry and BiotechnologyTechnical University BraunschweigBraunschweigGermany
  4. 4.Lonza BiopharmaceuticalsR&D Microbial ServicesVispSwitzerland

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