Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.1 (pyruvate carboxylase)
 1,516 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The catabolism of propane by "Nocardia paraffinicum" (Rhodococcus rhodochrous) has been shown to involve CO(2) fixation after its oxidation to propionic acid. "N. paraffinicum" failed to grow on either propane or 1-propanol in the absence of CO(2). The rate of propane utilization was directly related to the initial CO(2) concentration, and Warburg respirometry suggested that CO(2) was required for the catabolism of 1-propanol, propionaldehyde, and propionate but not for 2-propanol. These data also suggested that the predominant pathway for the utilization of propane by "N. paraffinicum" was through 1-propanol. The use of [2-C]propane and CO(2) confirmed the catabolism of propane and the fixation of CO(2). Through the use of these isotopes and the pyruvate carboxylase inhibitor sodium arsenite, the labeled 2,4-dinitrophenylhydrazine derivative of pyruvate was trapped and isolated via thin-layer chromatography. The trapping of [C]pyruvate in this manner was considered to be indicative of the presence of the methylmalonyl coenzyme A pathway for CO(2) fixation.
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PMID:Role of Carbon Dioxide in Catabolism of Propane by "Nocardia paraffinicum" (Rhodococcus rhodochrous). 1634 67

Corynebacterium glutamicum can utilize acetic acid and propionic acid for growth and amino acid production. Growth on acetate as sole carbon source requires acetate activation by acetate kinase (AK) and phosphotransacetylase (PTA), encoded in the pta-ack operon. Genetic and enzymatic studies showed that these enzymes also catalyze propionate activation and were required for growth on propionate as sole carbon source. However, when glucose was present as a co-substrate strain lacking the AK-PTA pathway was still able to utilize acetate or propionate for growth indicating that an alternative activation pathway exists. As shown by (13)C-labelling experiments, the carbon skeleton of acetate is conserved during activation to acetyl-CoA in this pathway. Metabolic flux analysis during growth on an acetate-glucose mixture revealed that in the absence of the AK-PTA pathway carbon fluxes in glycolysis, the tricarboxylic acid (TCA) cycle and anaplerosis via PEP carboxylase and/or pyruvate carboxylase were increased, while the glyoxylate cycle flux was decreased. DNA microarray experiments identified cg2840 as a constitutively and highly expressed gene putatively encoding a CoA transferase. Purified His-tagged Cg2840 protein was active as CoA transferase interconverting acetyl-, propionyl- and succinyl-moieties as CoA acceptors and donors. Strains lacking both the CoA transferase and the AK-PTA pathway could neither activate acetate nor propionate in the presence or absence of glucose. Thus, when these short-chain fatty acids are co-metabolized with other carbon sources, CoA transferase and the AK-PTA pathway constitute a redundant system for activation of acetate and propionate.
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PMID:Pathway identification combining metabolic flux and functional genomics analyses: acetate and propionate activation by Corynebacterium glutamicum. 1916 97

The effects of CO2 on propionic acid production and cell growth in glycerol or glucose fermentation were investigated in this study. In glycerol fermentation, the volumetric productivity of propionic acid with CO2 supplementation reached 2.94g/L/day, compared to 1.56g/L/day without CO2. The cell growth using glycerol was also significantly enhanced with CO2. In addition, the yield and productivity of succinate, the main intermediate in Wood-Werkman cycle, increased 81% and 280%, respectively; consistent with the increased activities of pyruvate carboxylase and propionyl CoA transferase, two key enzymes in the Wood-Werkman cycle. However, in glucose fermentation CO2 had minimal effect on propionic acid production and cell growth. The carbon flux distributions using glycerol or glucose were also analyzed using a stoichiometric metabolic model. The calculated maintenance coefficient (mATP) increased 100%, which may explain the increase in the productivity of propionic acid in glycerol fermentation with CO2 supplement.
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PMID:Effects of carbon dioxide on cell growth and propionic acid production from glycerol and glucose by Propionibacterium acidipropionici. 2545 45