Interactions between Carbon and Nitrogen Metabolism in Fibrobacter succinogenes S85: a 1 H and 13 C Nuclear Magnetic Resonance and Enzymatic Study
| Autor: | Tibor Liptaj, Christelle Matheron, Geneviève Gaudet, Anne-Marie Delort, Evelyne Forano |
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| Přispěvatelé: | Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Unité de Microbiologie (MIC), Institut National de la Recherche Agronomique (INRA) |
| Rok vydání: | 1999 |
| Předmět: |
Magnetic Resonance Spectroscopy
[SDV.BIO]Life Sciences [q-bio]/Biotechnology Nitrogen Alanine dehydrogenase Succinic Acid Biotechnologies spectroscopie rmn métabolisme de l'azote Applied Microbiology and Biotechnology chemistry.chemical_compound Nuclear magnetic resonance Ammonia Animals Amino Acids Amino acid synthesis Acetic Acid Alanine chemistry.chemical_classification Carbon Isotopes rumen Gram-Negative Anaerobic Bacteria Fibrobacter succinogenes Ecology Glycogen Chemistry Glutamate dehydrogenase métabolisme glucidique General Microbial Ecology Metabolism Carbon Kinetics fibrobacter Metabolic pathway Glucose Biochemistry fixation de l'ammonium Hydrogen Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology Applied and Environmental Microbiology, American Society for Microbiology, 1999, 65 (5), pp.1941-1948 Applied and Environmental Microbiology 5 (65), 1941-1948. (1999) |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.65.5.1941-1948.1999 |
| Popis: | The effect of the presence of ammonia on [1- 13 C]glucose metabolism in the rumen fibrolytic bacterium Fibrobacter succinogenes S85 was studied by 13 C and 1 H nuclear magnetic resonance (NMR). Ammonia halved the level of glycogen storage and increased the rate of glucose conversion into acetate and succinate 2.2-fold and 1.4-fold, respectively, reducing the succinate-to-acetate ratio. The 13 C enrichment of succinate and acetate was precisely quantified by 13 C-filtered spin-echo difference 1 H-NMR spectroscopy. The presence of ammonia did not modify the 13 C enrichment of succinate C-2 (without ammonia, 20.8%, and with ammonia, 21.6%), indicating that the isotopic dilution of metabolites due to utilization of endogenous glycogen was not affected. In contrast, the presence of ammonia markedly decreased the 13 C enrichment of acetate C-2 (from 40 to 31%), reflecting enhanced reversal of the succinate synthesis pathway. The reversal of glycolysis was unaffected by the presence of ammonia as shown by 13 C-NMR analysis. Study of cell extracts showed that the main pathways of ammonia assimilation in F. succinogenes were glutamate dehydrogenase and alanine dehydrogenase. Glutamine synthetase activity was not detected. Glutamate dehydrogenase was active with both NAD and NADP as cofactors and was not repressed under ammonia limitation in the culture. Glutamate-pyruvate and glutamate-oxaloacetate transaminase activities were evidenced by spectrophotometry and 1 H NMR. When cells were incubated in vivo with [1- 13 C]glucose, only 13 C-labeled aspartate, glutamate, alanine, and valine were detected. Their labelings were consistent with the proposed amino acid synthesis pathway and with the reversal of the succinate synthesis pathway. |
| Databáze: | OpenAIRE |
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