%0 Journal Article
%A Netzer, R.
%A Peters-Wendisch, P.
%A Eggeling, L.
%A Sahm, H.
%T Co-metabolism of a Non-Growth Substrate: L-Serine Utilization by Corynebacterium glutamicum
%J Applied and environmental microbiology
%V 70
%@ 0099-2240
%C Washington, DC [u.a.]
%I Soc.
%M PreJuSER-36935
%P 7148 - 7155
%D 2004
%Z Record converted from VDB: 12.11.2012
%X Despite its key position in central metabolism, L-serine does not support the growth of Corynebacterium glutamicum. Nevertheless, during growth on glucose, L-serine is consumed at rates up to 19.4 +/- 4.0 nmol min(-1) (mg [dry weight])(-1), resulting in the complete consumption of 100 mM L-serine in the presence of 100 mM glucose and an increased growth yield of about 20%. Use of 13C-labeled L-serine and analysis of cellularly derived metabolites by nuclear magnetic resonance spectroscopy revealed that the carbon skeleton of L-serine is mainly converted to pyruvate-derived metabolites such as L-alanine. The sdaA gene was identified in the genome of C. glutamicum, and overexpression of sdaA resulted in (i) functional L-serine dehydratase (L-SerDH) activity, and therefore conversion of L-serine to pyruvate, and (ii) growth of the recombinant strain on L-serine as the single substrate. In contrast, deletion of sdaA decreased the L-serine cometabolism rate with glucose by 47% but still resulted in degradation of L-serine to pyruvate. Cystathionine beta-lyase was additionally found to convert L-serine to pyruvate, and the respective metC gene was induced 2.4-fold under high internal L-serine concentrations. Upon sdaA overexpression, the growth rate on glucose is reduced 36% from that of the wild type, illustrating that even with glucose as a single substrate, intracellular L-serine conversion to pyruvate might occur, although probably the weak affinity of L-SerDH (apparent Km, 11 mM) prevents substantial L-serine degradation.
%K Bacterial Proteins: genetics
%K Bacterial Proteins: metabolism
%K Carbon Isotopes: metabolism
%K Corynebacterium glutamicum: growth & development
%K Corynebacterium glutamicum: metabolism
%K Culture Media
%K Gene Deletion
%K Glucose: metabolism
%K L-Serine Dehydratase: genetics
%K L-Serine Dehydratase: metabolism
%K Magnetic Resonance Spectroscopy
%K Oligonucleotide Array Sequence Analysis
%K Serine: metabolism
%K Bacterial Proteins (NLM Chemicals)
%K Carbon Isotopes (NLM Chemicals)
%K Culture Media (NLM Chemicals)
%K Glucose (NLM Chemicals)
%K Serine (NLM Chemicals)
%K L-Serine Dehydratase (NLM Chemicals)
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:15574911
%2 pmc:PMC535176
%U <Go to ISI:>//WOS:000225719300026
%R 10.1128/AEM.70.12.7148-7155.2004
%U https://juser.fz-juelich.de/record/36935