/sup 13/C nuclear magnetic resonance studies of the biosynthesis by Microbacterium ammoniaphilum of L-glutamate selectively enriched with carbon-13
/sup 13/C NMR of isotopically enriched metabolites has been used to study the metabolism of Microbacterium ammoniaphilum, a bacterium which excretes large quantities of L-glutamic acid into the medium. Biosynthesis from 90% (1-/sup 13/C) glucose results in relatively high specificity of the label, with (2,4-/sup 13/C/sub 2/) glutamate as the major product. The predominant biosynthetic pathway for synthesis of glutamate from glucose was determined to be the Embden Meyerhof glycolytic pathway followed by P-enolpyruvate carboxylase and the first third of the Krebs cycle. Different metabolic pathways are associated with different correlations in the enrichment of the carbons, reflected in the spectrum as different /sup 13/C-/sup 13/C scalar multiplet intensities. Hence, intensity and /sup 13/C-/sup 13/C multiplet analysis allows quantitation of the pathways involved. Although blockage of the Krebs cycle at the ..cap alpha..-ketoglutarate dehydrogenase step is the basis for the accumulation of glutamate, significant Krebs cycle activity was found in glucose grown cells, and extensive Krebs cycle activity in cells metabolizing (1-/sup 13/C) acetate. In addition to the observation of the expected metabolites, the disaccharide ..cap alpha..,..cap alpha..-trehalose and ..cap alpha..,..beta..-glucosylamine were identified from the /sup 13/C NMR spectra.
- Research Organization:
- Los Alamos National Lab., NM
- OSTI ID:
- 5177638
- Journal Information:
- J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 257:3; ISSN JBCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550701 -- Microbiology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
AMINO ACIDS
BACTERIA
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
CARBOHYDRATES
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
ENZYME ACTIVITY
EVEN-ODD NUCLEI
GLUCOSE
GLUTAMIC ACID
HEXOSES
ISOTOPE APPLICATIONS
ISOTOPES
KREBS CYCLE
LABELLED COMPOUNDS
LIGHT NUCLEI
MAGNETIC RESONANCE
METABOLISM
METABOLITES
MICROORGANISMS
MONOSACCHARIDES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RESONANCE
SACCHARIDES
STABLE ISOTOPES
SYNTHESIS
TRACER TECHNIQUES