Glucose Catabolism in Strains of Acidophilic, Heterotrophic Bacteria (original) (raw)
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Biotechnology Progress, 1990
Escherichia coli HB101 was grown in complex medium under anaerobic and aerobic conditions. Cells prepared under these two different conditions were characterized by two‐dimensional protein gel electrophoresis, by NMR measurements under identical (anaerobic) conditions, and by measuring the kinetics of glucose uptake and catabolite end‐product appearance in the medium under identical anaerobic conditions. Specific rates of glucose uptake and end‐product formation were significantly greater for the anaerobically grown cells, which also exhibited lower intracellular concentrations of sugar phosphates, nucleoside di‐and triphosphates, UDPG, and NAD(H). Two‐dimensional gel electrophoretic analyses reveal changes in the intracellular levels of proteins involved in pyruvate catabolism that have been observed previously for E. coli grown in minimal medium under aerobic and anaerobic conditions. Enzymes involved in the TCA cycle were not detected in cells grown aerobically or anaerobically i...
Taxonomic diversity of the D-glucose oxidation pathway in the Enterobacteriaceae
… journal of systematic …, 1989
Tests allowing the screening of large numbers of enterobacterial strains for the presence of the glucose oxidation pathway (glucose, gluconate, and 2-ketogluconate dehydrogenases) were devised or adapted. A total of 506 strains representing 111 taxa (named species or subspecies and unnamed genomic groups) were studied. The members of the genera Budvicia, Edwardsiella, Leminorella, Providencia, and Xenorhabdus and the species Citrobacter freundii, Erwinia carnegeana, Erwinia carotovora, Erwinia chrysanthemi, Erwinia nignpuens, Erwinia salicis, Moellerella wisconsensis, Proteus penneri, Proteus vulgaris, Yersinia intermedia, Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia ruckeri were negative in all tests. Five species, Erwinia cypripedii, E wingella americana, Rahnella aquatilis, Serratia marcescens (at 20"C), and Tatumella ptyseos produced 2,s-diketogluconate from glucose without a requirement for pyrroloquinoline quinone (PQQ). When PQQ was provided (required for glucose oxidation), Serratia grimesii and Serratia liquefaciens produced 2,5-diketogluconate from glucose at 20°C. Escherichia blattae had gluconate-and 2-ketogluconate dehydrogenases without glucose dehydrogenase. The members of the genera Hafnia, Obesumbacterium, and Pragia had only gluconate dehydrogenase. Other species had glucose dehydrogenase (with or without a requirement for PQQ) with or without gluconate dehydrogenase. Classification and identification may take advantage of tests exploring the glucose oxidation pathway.
Extracellular oxidation of D-glucose by some members of the Enterobacteriaceae
Annales de l'Institut Pasteur. Microbiology
Extracellular D-glucose oxidation by 5 enterobacterial species was studied with the purpose of selecting conditions useful for taxonomic studies. Extracellular production of gluconate from 14C-glucose by bacterial cells was evidenced by DEAE-cellulose paper chromatography. Escherichia coli oxidized glucose only when pyrroloquinoline quinone (PQQ) was added, whereas Serratia marcescens, Yersinia frederiksenii, Erwinia cypripedii and Cedecea lapagei oxidized D-glucose without added PQQ. 2-Deoxyglucose was found to be an excellent non-metabolized analogue of D-glucose in oxidation experiments. D-glucose oxidation was inhibited by KCN, p-chloromercuribenzoic acid and carbonyl cyanide m-chlorophenylhydrazone; and activated by p-benzoquinone. Iodoacetate had no action. Comparative cellulose thin-layer chromatography including 2-ketogluconate and 2,5-diketogluconate (produced by Janthinobacterium lividum) as standards, showed that gluconate was oxidized to 2-ketogluconate by S. marcescens ...
Glucose Metabolism in Batch and Continuous Cultures of Gluconacetobacter diazotrophicus PAL 3
Current Microbiology, 2006
Periplasmic glucose oxidation (by way of a pyrrolo-quinoline-quinone [PQQ]-linked glucose dehydrogenase [GDH]) was observed in continuous cultures of Gluconacetobacter diazotrophicus regardless of the carbon source (glucose or gluconate) and the nitrogen source (N 2 or NH 3 ). Its synthesis was stimulated by conditions of high energetic demand (i.e., N 2 -fixation) and/or C-limitation. Under C-excess conditions, PQQ-GDH synthesis increased with the glucose concentration in the culture medium. In batch cultures, PQQ-GDH was actively expressed in very early stages with higher activities under conditions of N 2 -fixation. Hexokinase activity was almost absent under any culture condition. Cytoplasmic nicotinamide adenine dinucleotide (NAD)-linked glucose dehydrogenase (GDH) was expressed in continuous cultures under all tested conditions, and its synthesis increased with the glucose concentration. In contrast, low activities of this enzyme were detected in batch cultures. Periplasmic oxidation, by way of PQQ-GDH, seems to be the principal pathway for metabolism of glucose in G. Diazotrophicus, and NAD-GDH is an alternative route under certain environmental conditions.
Glucose Metabolism by Lactobacillus divergens
Microbiology, 1988
Earlier studies on the fermentation of D-[ 1-14C]-and D-[ 3,4-14C]glucose by Lactobacillus divergens showed that lactate was the major fermentation product and that it was probably produced by glycolysis. It was therefore recommended that L. divergens be reclassified as a homofermentative organism. In the present investigation, products of D-[ 1-14C]-, D-[2-14C]-and D-[ 3,4-14C]glucose fermented by L. divergens were isolated, and their specific radioactivities and the distribution patterns of radioactivity in their C-atoms were determined. The positional labelling patterns of the fermentation products, their specific radioactivities and their concentrations confirmed that glucose is degraded via the glycolytic pathway. Some secondary decarboxylation/dissimilation of pyruvate to acetate, formate and C 0 2 was also observed. These results provide conclusive proof that L. divergens is indeed a homofermentative organism. Results obtained with D-[ U-14C]glucose showed that approximately three-quarters of the lactate but less than 10% each of the formate and acetate were produced from glucose. The remainder was presumably derived to a varying degree from endogenous non-glucose sources such as fructose and/or amino acids. I N T R O D U C T I O N Lactobacillus divergens, isolated from vacuum-packaged meat, was initially classified as an atypical heterofermentative organism (Holzapfel & Gerber, 1983). Recent radioactivity incorporation studies with D-[ I-l4C]-and ~-[3,4-l SC]glucose as substrates have, however, suggested that L. dioergens metabolizes glucose principally by the glycolytic pathway (De Bruyn et al., 1987), and it was recommended that the organism be reclassified as a homofermentative organism. These studies have now been extended to provide information on the distribution of the 14Clabel in the fermentation products of D-[ l-l4C]-, D-[2-14C]-and D-[3,4-'4C]glUCOSe. The results allow definitive conclusions to be drawn on the principal route by which L. divergens metabolizes glucose. METHODS Strain and materials. Lactobacillus divergens, isolate 66 (DSM 20623), from our collection (Holzapfel & Gerber, 1983) was used. ~-[ l -~~C ] G l u c o s e [specific activity 53.4 mCi mmol-' (1 mCi = 37 MBq)], ~-[2-~~C]glucose (49.3 mCi mmol-I) and ~-[3,4-~~C]glucose (10.32 mCi mmol-l) were obtained from New England Nuclear. D-[U-
Microbiology, 1994
Periplasmic oxidation of glucose into gluconate and 2-ketogluconate in Klebsiella pneumoniae occurs via glucose dehydrogenase (GDH) and gluconate dehydrogenase (GaDH), respectively. Since, as is shown here, in the presence of glucose, gluconate and 2-ketogluconate are not further metabolized intracellularly the physiological function of t h i s periplasmic route was studied. It was found that periplasmic oxidation of glucose could function as an alternative production route of ATP equivalents. Instantaneous activation of either GDH or GaDH reduced the rate of degradation of glucose via glycolysis and the tricarboxylic acid (TCA) cycle in vivo. Furthermore, aerobic, magnesium-and phosphate-limited chemostat cultures with glucose as the carbon source showed high GDH plus GaDH activities in contrast to nitrogenand sulphate-limited cultures. However, when fructose, which is not degraded by GDH, was the carbon source, specific oxygen consumption rates under these four conditions were essentially the same. The latter observation suggests that high transmembrane phosphate gradients which are supposedly present under phosphate-limited conditions do not cause high energetic demands due t o futile cycling of phosphate ions. In addition, dissipation of the transmembrane phosphate gradient of phosphate-limited cells immediately increased the rate of intracellular glucose degradation. It is concluded that under phosphatelimited conditions (i) extensive futile cycling of phosphate ions is absent and (ii) low concentrations of phosphate ions limit intracellular degradation of glucose. Glyceraldehyde-3-phosphate dehydrogenase (GADPH) activities of cell-free extracts of glucose-grown cells harvested from aerobic chemostat cultures limited in various nutrients showed that a t least a tenfold overcapacity in GAPDH activity was present under phosphate-limited conditions with respect to the steady-state carbon fluxes through this enzyme. The physiological significance of t h i s adaptation and the possible role of GDH and GaDH are discussed.