Format

Send to

Choose Destination
Appl Microbiol Biotechnol. 2007 Sep;76(3):615-23. Epub 2007 Mar 2.

Effect of pyruvate dehydrogenase complex deficiency on L-lysine production with Corynebacterium glutamicum.

Author information

1
Institute of Microbiology and Biotechnology, University of Ulm, 89069, Ulm, Germany.

Abstract

Intracellular precursor supply is a critical factor for amino acid productivity of Corynebacterium glutamicum. To test for the effect of improved pyruvate availability on L-lysine production, we deleted the aceE gene encoding the E1p enzyme of the pyruvate dehydrogenase complex (PDHC) in the L-lysine-producer C. glutamicum DM1729 and characterised the resulting strain DM1729-BB1 for growth and L-lysine production. Compared to the host strain, C. glutamicum DM1729-BB1 showed no PDHC activity, was acetate auxotrophic and, after complete consumption of the available carbon sources glucose and acetate, showed a more than 50% lower substrate-specific biomass yield (0.14 vs 0.33 mol C/mol C), an about fourfold higher biomass-specific L-lysine yield (5.27 vs 1.23 mmol/g cell dry weight) and a more than 40% higher substrate-specific L-lysine yield (0.13 vs 0.09 mol C/mol C). Overexpression of the pyruvate carboxylase or diaminopimelate dehydrogenase genes in C. glutamicum DM1729-BB1 resulted in a further increase in the biomass-specific L-lysine yield by 6 and 56%, respectively. In addition to L-lysine, significant amounts of pyruvate, L-alanine and L-valine were produced by C. glutamicum DM1729-BB1 and its derivatives, suggesting a surplus of precursor availability and a further potential to improve L-lysine production by engineering the L-lysine biosynthetic pathway.

PMID:
17333167
DOI:
10.1007/s00253-007-0904-1
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center