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At least 19 recordsLinked to original sources
PubMed2002

Anaeroglobus geminatus gen. nov., sp. nov., a novel member of the family Veillonellaceae.

A hitherto unknown anaerobic coccus isolated from a post-operative fluid collection was characterized by phenotypic and phylogenetic methods. 16S rDNA sequence analysis revealed an affiliation of this isolate to the family Veillonellaceae. Also, a high level of sequence similarity was observed to some oral clone sequences of Megasphaera spp. contained in the GenBank database under designations BB166, CS025 and BS073. These clones and the unknown bacterium form a well-separated phylogenetic branch that may represent a novel lineage within the family Veillonellaceae. Based on phenotypic and phylogenetic evidence, a new genus, Anaeroglobus gen. nov., is proposed for the unknown bacterium, with one species, Anaeroglobus geminatus gen. nov., sp. nov. The type strain of Anaeroglobus geminatus is strain AIP 313.00T (= CIP 106856T = CCUG 44773T). It is also suggested that the oral clones BB166, CS025 and BS073 belong to the genus Anaeroglobus.

Aged↗
PubMed1975

Rapid screening of Veillonella by ultraviolet fluorescence.

Among 51 strains of anaerobic gram-negative cocci belonging to the family Veillonellaceae, all strains of Veillonella (V. parvula and V. alcalescens) displayed red fluorescence under long-wave (366 nm) ultraviolet light, whereas no Acidaminococcus or Megasphaera demonstrated fluorescence. In contrast to Bacteroides melaninogenicus, growth of Veillonella does not require hemin and menadione, and flourescence is rapidly lost upon exposure to air. The fluorescent component of a strain of V. parvula examined could not be extracted in solution with water, ether, methanol, or chloroform, but was readily extracted with 0.4 N NaOH. Spectrophotofluorometrically, the fluorescence maximum of this extract was 660 nm with an excitation maximum of 300 nm, when measured at pH 7.2 and 25 C. Coupled with the Gram stain, ultraviolet fluorescence may be a useful tool for rapid screening of Veillonella and is particularly helpful for detection and, isolation of this organism from mixed culture.

Air↗
PubMed1990

[Effect of BMY-28100 on bacterial flora in adult human feces].

We investigated effects of BMY-28100 on fecal bacteria. BMY-28100 was administered orally to 8 healthy male volunteers between 20 and 24 years of age weighing between 58.0 and 79.5 kg. All subjects were given one 250 mg capsule 3 times a day at 30 minutes after meal for 7 days. Fecal bacterial counts were examined 5 days before the start of administration, the day of the start of administration, 3, 5 and 7 days after the start of administration, and 3, 5, 10, 20 and 30 days after the end of administration. Concentrations of BMY-28100 and Clostridium difficile D-1 toxin in feces were also examined together with examinations for adverse reactions and abnormal laboratory test values. 1. Total aerobic bacterial counts increased transiently upon the antibiotic dosage. Escherichia coli and yeast like organism increased transiently during the period of administration, while the total counts of anaerobic bacteria remained constant. Veillonellaceae, Peptococcaceae and Eubacterium decreased transiently during the period of administration. Although C. difficile and its D-1 toxin were detected in 1 and 5 cases, respectively, these feces appeared normal. 2. Active metabolites of BMY-28100 were not detected in the feces. 3. No adverse effects or no abnormal laboratory test values were observed.

Administration, Oral↗
PubMed1981

Regulation of lactate metabolism in the rumen.

The regulation of lactic acid production, the regulation of lactate fermentation and the role of lactate as intermediate in the rumen metabolism was studied. The pH had a pronounced effect on all three processes and therefore buffer capacity of the rumen contents is also described. Starch gave much less rise to lactic acidosis than soluble sugars, as glucose and fructose. Most bacteria grow faster and therefore produce more lactic acid when amino acids and/or soluble proteins are present in the diet. Activity of LDH (lactate dehydrogenase) of mixed rumen microorganisms is regulated by the NADH/NAD(H) balance and the ATP concentration. About 60% of the LDH in mixed rumen microorganisms is fructose-1, 6-diphosphate independent. Megasphaera elsdenii ferments 60 to 80% of the lactate fermented in the rumen of dairy cattle. Lactate accumulates only when the glycolytic flux (hexose units fermented per unit time per microorganism) is high. During adaptation, the glycolytic flux is increased and lactate may accumulate. After adaptation to a certain diet, the number of microorganisms is changed and the glycolytic flux again is normal and lactate is only a minor intermediate in rumen metabolism.

Animals↗
PubMed1993

Monensin has no effect on growth and metabolism of Megasphaera elsdenii.

A rumen strain of Megasphaera elsdenii was grown on glucose and lactate in monensin-free and monensin-supplemented medium (10 mg/L). Monensin had no effect on growth rate, growth yields, metabolic pattern and composition of cells. Growth yields of dry matter and protein were higher in cultures supplied with glucose than in cultures supplied with lactate. The bacterium compensated the lower gain of energy from fermentation of lactate by rapid utilization of this substrate. Cells grown on glucose contained more saccharide and less protein than lactate-grown cells.

Animals↗
PubMed2004

GATC-specific restriction--modification systems in ruminal bacteria.

The GATC-specific restriction and modification activities were analyzed in 11 major bacterial representatives of ruminal microflora. Modification phenotype was observed in 13 out of 40 ruminal strains. MboI isoschizomeric restriction endonucleases were detected in 10 bacterial strains tested; three strains lacked any detectable corresponding endonuclease activity. The only examined strain of Mitsuokella multi-acida was found to possess a different type of endonuclease activity. This is the first report on restriction activity in ruminal treponemes M. multiacida and Megasphaera elsdenii.

Animals↗
PubMed2004

Desulfosporomusa polytropa gen. nov., sp. nov., a novel sulfate-reducing bacterium from sediments of an oligotrophic lake.

Five strains of sulfate-reducing bacteria were isolated from the highest positive dilutions of a most probable number (MPN) series supplemented with lactate and inoculated with sediments from the oligotrophic Lake Stechlin. The isolates were endospore-forming and were motile by means of laterally inserted flagella. They stained Gram-negative and contained b-type cytochromes. CO difference spectra indicated the presence of P582 as a sulfite reductase. Phylogenetic analyses of the 16S rDNA sequences revealed that the isolates were very closely affiliated with the genus Sporomusa. However, sulfate and amorphous Fe(OH)(3), but not sulfite, elemental sulfur, MnO(2), or nitrate were used as terminal electron acceptors. Homoacetogenic growth was found with H(2)/CO(2) gas mixture, formate, methanol, ethanol, and methoxylated aromatic compounds. The strains grew autotrophically with H(2) plus CO(2) in the presence or absence of sulfate. Formate, butyrate, several alcohols, organic acids, carbohydrates, some amino acids, choline, and betaine were also utilized as substrates. The growth yield with lactate and sulfate as substrate was 7.0 g dry mass/mol lactate and thus two times higher than in sulfate-free fermenting cultures. All isolates were able to grow in a temperature range of 4-37 degrees C. Physiologically and by the presence of a Gram-negative cell wall, the new isolates resemble known Desulfosporosinus species. However, phylogenetically they are affiliated with the Gram-negative genus Sporomusa belonging to the Selenomonas subgroup of the Firmicutes. Therefore, the new isolates reveal a new phylogenetic lineage of sulfate-reducing bacteria. A new genus and species, Desulfosporomusa polytropa gen. nov., sp. nov. is proposed.

Bacterial Typing Techniques↗
PubMed2006

Sporotalea propionica gen. nov. sp. nov., a hydrogen-oxidizing, oxygen-reducing, propionigenic firmicute from the intestinal tract of a soil-feeding termite.

An unusual propionigenic bacterium was isolated from the intestinal tract of the soil-feeding termite Thoracotermes macrothorax. Strain TmPN3 is a motile, long rod that stains gram-positive, but reacts gram-negative in the KOH test. It forms terminal endospores and ferments lactate, glucose, lactose, fructose, and pyruvate to propionate and acetate via the methyl-malonyl-CoA pathway. Propionate and acetate are formed at a ratio of 2:1, typical of most propionigenic bacteria. Under a H(2)/CO(2) atmosphere, the fermentation product pattern of glucose, fructose, and pyruvate shifts towards propionate formation at the expense of acetate. Cell suspensions reduce oxygen with lactate, glucose, glycerol, or hydrogen as electron donor. In the presence of oxygen, the product pattern of lactate fermentation shifts from propionate to acetate production. 16S rRNA gene sequence analysis showed that strain TmPN3 is a firmicute that clusters among the Acidaminococcaceae, a subgroup of the Clostridiales comprising obligately anaerobic, often endospore-forming bacteria that possess an outer membrane. Based on phenotypic differences and less than 92% sequence similarity to the 16S rRNA gene sequence of its closest relative, the termite hindgut isolate Acetonema longum, strain TmPN3(T) is proposed as the type species of a new genus, Sporotalea propionica gen. nov. sp. nov. (DSM 13327(T), ATCC BAA-626(T)).

Animals↗
PubMed2004

Nutritional requirements of Allisonella histaminiformans, a ruminal bacterium that decarboxylates histidine and produces histamine.

Histamine is an inflammatory agent that contributes to bovine laminitis. Cattle fed silage-containing rations often have large populations of Allisonella histaminiformans, but this obligate histidine-decarboxylating bacterium could not be isolated from cattle fed timothy hay. The growth of A. histaminiformans was stimulated by yeast extract, protein hydrolysates, and water-soluble extracts of alfalfa or corn silage. Extracts of alfalfa were more potent than corn silage. Because growth and histamine production were not stimulated by Casamino Acids or a mixture of purified amino acids, it appeared that A. histaminiformans requires peptides. The idea that A. histaminiformans requires peptides is consistent with the observation that alfalfa silages often have a large amount of peptide nitrogen.

Animal Feed↗
PubMed2000

Factors affecting glucose and maltose phosphorylation by the ruminal bacterium Megasphaera elsdenii.

The objectives of this study were to examine the effects of growth substrate and extracellular pH on phosphoenolpyruvate-dependent glucose phosphorylation as well as to examine how maltose is phosphorylated by the ruminal bacterium Megasphaera elsdenii B159. Phosphoenolpyruvate-dependent glucose phosphorylation by toluene-treated cells was constitutive, and glucose phosphorylation was reduced by 69% at pH 5.0. When toluene-treated cells were incubated in histidine buffer, little maltose phosphorylation occurred in the absence of inorganic phosphate. However, the addition of increasing concentrations of either potassium or sodium phosphate increased maltose phosphorylation. Maximal phosphorylation activity was observed at between 25 and 50 mM of either inorganic phosphate source. Compared with the control incubations, maltose phosphorylation was increased over threefold with 25 mM of either potassium or sodium phosphate. Phosphoglucomutase activity was detected in cell extracts of M. elsdenii B159, and this enzyme had a K(m) of 3.2 mM for glucose-1-P and a V(max) of 1836 nmol of NADP(+) reduced/mg of protein per min. Maltose was also hydrolyzed by an inducible maltase (K(m), 1.19 mM). To our knowledge, this is the first report of a maltose phosphorylase and a maltase in M. elsdenii.

Animals↗
PubMed1990

Physical studies on the membranes and lipids of plasmalogen-deficient Megasphaera elsdenii.

Membrane fluidity and thermotropic phase behavior in the wild-type and plasmalogen-deficient strains of Megasphaera elsdenii have been studied by means of diphenylhexatiene steady state fluorescence anisotropy in isolated membranes, and by 31P-NMR and X-ray diffraction of the isolated phospholipids. Compared to the wild-type plasmalogen content of greater than 75%, plasmalogen-deficient strains had less than 5% plasmalogen, consisting largely of phosphatidylethanolamine and phosphatidylserine. Steady state fluorescence anisotropy measurements yielded an order parameter which was 6% lower in the plasmalogen-deficient membranes from 10 degrees to 40 degrees C, indicating higher membrane lipid mobilities. Both 31P-NMR and X-ray diffraction revealed the formation of a hexagonal phase in the lipids from the wild-type strain starting above 30 degrees C. In general the transition was not complete by 80 degrees C. In contrast, phospholipids from plasmalogen-deficient strains appeared to form a relatively stable lamellar phase.

Cell Membrane↗
PubMed1982

A photo-CIDNP study of the active sites of Megasphaera elsdenii and Clostridium MP flavodoxins.

Megasphaera elsdenii and Clostridium MP flavodoxins have been investigated by photo-CIDNP techniques. Using time-resolved spectroscopy and external dyes carrying different charges it was possible to assign unambiguously the resonance lines in the NMR-spectra to tyrosine, tryptophan and methionine residues in the two proteins. The results show that Trp-91 in M.elsdenii and Trp-90 in Cl.MP flavodoxin are strongly immobilized and placed directly above the benzene subnucleus of the prosthetic group. The data further indicate that the active sites of the two flavodoxins are extremely similar.

Binding Sites↗
PubMed1993

Identification of the gene encoding the activator of (R)-2-hydroxyglutaryl-CoA dehydratase from Acidaminococcus fermentans by gene expression in Escherichia coli.

(R)-2-Hydroxyglutaryl-CoA dehydratase (HGDA/B) from Acidaminococcus fermentans requires an activator protein for activity. This activator (HGDC) has not yet been purified from its natural source due to its low concentration combined with an extreme sensitivity towards oxygen. Gene expression in Escherichia coli identified an open reading frame (780 bp) as the gene encoding HGDC. Dehydratase activity was stimulated at least tenfold by cell-free extracts of E. coli cells transformed with a plasmid carrying hgdC. On the chromosome the hgdC gene is located just before hgdA and hgdB.

Amino Acid Sequence↗
PubMed1984

Inhibition of the autoxidation of ascorbate and norepinephrine by extracts of Clostridium butyricum, Megasphaera elsdenii and Escherichia coli.

The autoxidation of ascorbate and of norepinephrine in Krebs Ringer phosphate medium, pH 7.4, was studied. The autoxidation of the two substances was determined spectrophotometrically at 265 and 480 nm respectively. The effect of dialyzed extracts (m.w. greater than 12,000) from Escherichia coli (aerobe), Megasphaera elsdenii, and Clostridium butyricum (obligate anaerobes) was examined and compared to similarly prepared extracts from rat serum and cerebral cortex. The assay medium contained cellular components diluted 10(3)-10(6)-fold. Up to 10(4)-fold dilution there was a substantial reduction in the rate of both autoxidation reactions, but the preparations from M. elsdenii and C. butyricum were conspicuously less effective. After 5 min heat treatment at 100 degrees C the anaerobic preparations produced less than 20% inhibition, while the activity of the other preparations remained unchanged at 75-95% inhibition. These and earlier experiments involving additional mammalian species (Mishra and Kovachich, Neurosci. Lett., 43: 103-108, 1983) and plants (Mishra and Kovachich, Life Sci., 34: 2207-2212, 1984) suggest that a high level of heat-stable antioxidant activity in one or both of these autoxidation tests (denatured plant extracts only inhibit ascorbate autoxidation) is a general characteristic of organisms that thrive in oxygen-rich atmosphere.

Animals↗
PubMed1987

Redox properties of electron-transferring flavoprotein from Megasphaera elsdenii.

Electron-transferring flavoprotein (ETF) from the anaerobic bacterium Megasphaera elsdenii catalyzes electron transfer from NADH or D-lactate dehydrogenase to butyryl-CoA dehydrogenase. As a basis for understanding the interactions of ETF with its substrates, we report here on the redox properties of ETF alone. ETF exhibited reversible, two-electron transfer during electrochemical reduction in the presence of mediator dyes. The midpoint redox potentials of the FAD cofactor were -0.185 V at pH 5.5, -0.259 V at pH 7.1 and -0.269 +/- 0.013 V at pH 8.4, all versus the standard hydrogen electrode In the presence of the indicator dye 1-deazariboflavin, the Nernst slopes were 0.029 V and 0.026 V at pH 5.5 and pH 7.1, respectively, compared with an expected value of 0.028 V at 10 degrees C. At pH 8.4, in the presence of 2-hydroxy-1,4-naphthoquinone or phenosafranine, the Nernst slope varied from 0.021 V to 0.041 V. In the experiments at pH 8.4, equilibration was very slow in the reductive direction and a difference of as much as 30 mV was observed between reductive and oxidative midpoints. ETF exhibited no thermodynamic stabilization of the radical form of the FAD cofactor during electrochemical reduction at pH 5.5, 7.1 or 8.4. However, up to 93% of kinetically stable, anionic radical was produced by dithionite titration at pH 8.5. Molar absorptivities of ETF radical were 17,000 M-1 X cm-1 at 365 nm and 5100 M-1 X cm-1 at 450 nm. The four ETF preparations used here contained less than 7% 6-OH-FAD. However, two of the preparations contained significant amounts (up to 30%) of flavin which stabilized radical and reduced at potentials 0.2 V more positive than those required for reduction of the major form of ETF. This is referred to as the B form of ETF. The proportion of ETF-FAD in the B form was increased by incubation with free FAD or by a cycle of reduction and reoxidation. These treatments caused marked changes in the absorption spectrum of oxidized ETF and decreases of 20-25% in ETF units/A450.

Butyryl-CoA Dehydrogenase↗
PubMed1992

Phylogenetic and chemotaxonomic characterization of Acidaminococcus fermentans.

The phylogenetic position of Acidaminococcus fermentans was determined by comparative sequence analysis of the 16S rRNA. This Gram-negative bacterium is a member of the Sporomusa cluster that is defined by other Gram-negative bacteria, i.e. Sporomusa, Megasphaera, Selenomonas, Butyrivibrio, Pectinatus, and Zymophilus. The branching point of this group within the radiation of Gram-positive bacteria of the Clostridium/Bacillus subphylum and adjacent to Peptococcus niger could be confirmed. Chemotaxonomic data were provided for a more detailed characterization of A. fermentans.

Amino Acids, Diamino↗