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PubMed1982

Features of a Clostridium, strain CV-AA1, an obligatory anaerobic bacterium producing acetic acid from methanol.

Isolation and characterization of a new, obligatory, anaerobic, methylotrophic, homoacetogenic bacterium is described. This bacterium is a mesophilic, motile, slightly curved rod that demonstrated a negative Gram reaction, formed spherical, (sub)terminal spores and performed a homoacetic fermentation with methanol, a CO2-2H2-gas mixture, glucose or fructose, respectively, as the substrate. The methanol fermentation proceeded only when a suitable amount of NaHCO3 was available in the nutrient solution supplied.

Acetates↗
PubMed1976

Isolation of a moderate halophilic ammonia-oxidizing bacterium, Nitrosococcus mobilis nov. sp.

An ammonia-oxidizing bacterium was isolated from a sample of brackish water (North Sea, Harbour of Husum). It is a motile large coccus 1.5-1.7 mum in diameter. The extensive cytomembrane system occurring as flattened vesicles in the peripheral region of the cytoplasm and as intrusions into the center of the cytoplasm is to be emphasized as a characteristic mark of identification. The lithoautotrophically growing bacterium turned out to be an obligate halophile. Because of its physiological and morphological properties, we assigned it to the genus Nitrosococcus and propose the name Nitrosococcus mobilis.

Bradyrhizobiaceae↗
PubMed1976

The characterization of the rumen bacterium Eadie's oval, Magnoovum gen. nov. eadii sp. nov.

The rumen bacterium Eadie's Oval was examined by means of cell wall analysis and biochemical tests with a view to determine its taxonomic position. The purified cell walls contained components consistent with the organism being a Gram-negative bacterium, and despite its large size no abnormal cell wall constituents were found. The biochemical tests indicate that Eadie's Oval is not a member of a previously described family. The name Magnoovum gen. nov. eadii sp. nov. is proposed.

Animals↗
PubMed1977

A new anaerobic, sporing, acetate-oxidizing, sulfate-reducing bacterium, Desulfotomaculum (emend.) acetoxidans.

A new strictly anaerobic, polarly flagellated, sporing, acetate-oxidizing, sulfate-reducing bacterium was isolated from anaerobic fresh or sea water mud samples. The oxidation of acetate to CO2 is stoichiometrically linked to the formation of H2S from sulfate. Ethanol, butanol and butyrate are also used. Hydrogen, lactate or pyruvate are not used as electron donors; organic substances are not fermented. A cytochrome of the b-type and a supposed sulfite reductase, P582, were detected spectrophotometrically. An emended description of the genus Desulfotomaculum is proposed which includes the new bacterium as the species Desulfotomaculum acetoxidans.

Acetates↗
PubMed1984

An evaluation of the conditions necessary for optimal protein A-gold labelling of capsular antigen in ultrathin methacrylate sections of the bacterium Pasteurella haemolytica.

The protein A-gold (PAG) probe is a particulate immunocytochemical probe that is eminently suitable for quantification. In order to obtain critical results from the technique, a specific and reproducible probe is needed. To this end, the concentration of probe, the variation of labelling on different sections within a single grid, the effect of washing procedures, the variation of labelling with time and temperature and the effect of different storage conditions on the probe have been investigated using PAG labelling of capsular antigen on ultrathin methacrylate sections of the bacterium Pasteurella haemolytica. The results indicate that in this antigen-antibody system, and using a 20 nm probe, optimal results are achieved with 2 X 10(12) particles/ml, a labelling time of 60 min at room temperature and the PAG probe, which will have been stored at 4 degrees C, should be between 1- and 5-weeks-old. The efficiency of the probe is tested by evaluating different primary antibody concentrations, by evaluating cross reactions of the primary antibody and by evaluating the relative amounts of antibody against internal components of the bacterium present in different antisera.

Antigens, Bacterial↗
PubMedDate not supplied

Septicaemia with a dysgonic fermenter-2 (DF-2) bacterium in a compromised host.

Dysgonic fermenter-2 (DF-2) is a newly described gram-negative bacterium that can produce serious infections in the compromised host. We are reporting a case of DF-2 septicaemia in a splenectomized patient with chronic lymphocytic leukaemia. The clinical spectrum of infections due to the DF-2 bacterium, the difficulties in establishing the diagnosis and the preferential treatment are discussed.

Agammaglobulinemia↗
PubMed1993

Trans-monoenoic and polyunsaturated fatty acids in phospholipids of a Vibrio species of bacterium in relation to growth conditions.

A Vibrio species of bacterium known to contain the polyunsaturated fatty acid 20:5n-3 was grown in both freshwater and seawater media at 5 and 20 degrees C and examined for adaptive changes in lipid composition. Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), together with a smaller proportion of nonesterified fatty acids (NEFA), comprised almost all the lipid under all growth conditions examined. Temperature had a more pronounced effect than the salinity of the medium on lipid composition. The proportion of PE in total lipid was always higher at 5 than at 20 degrees C. Conversely, the proportion of NEFA was lower at 5 than 20 degrees C whereas that of PG was not altered. The levels of saturated fatty acids in total lipid, PE and PG were all decreased by growth at 5 degrees C. No differences were observed with respect to growth temperature in the levels of cis 16:1n-7, the principal monoenoic fatty acid in both PE and PG. Trans 16:1n-7 was found to comprise 12.8-15.2% of fatty acids in PE and PG of bacteria grown at 5 degrees C but only 4.4-8.5% of phospholipid fatty acids in bacteria cultured at 20 degrees C. Regardless of medium composition, a reduction in growth temperature from 20 to 5 degrees C also caused the proportions of 20:5n-3 to increase from around 0.8 to 4.4% in PE and from around 4 to 20% in PG. The simultaneous occurrence of trans 16:1n-7 and 20:5n-3 is unique to this Vibrio species of bacterium.(ABSTRACT TRUNCATED AT 250 WORDS)

Fatty Acids↗
PubMed2004

Synergic activity of selenium and probiotic bacterium Enterococcus faecium M-74 against selected mutagens in Salmonella assay.

Concentrated extracts of MRS (De Man-Rogosa-Sharpe) media in which probiotic bacterium Enterococcus faecium strain M-74 was grown exerted different antimutagenic activity against ofloxacin-, N-methyl, N'-nitro-N-nitrosoguanidine- and sodium 5-nitro-2-furylacrylate-induced mutagenicity in Salmonella typhimurium assay depending on the presence (+Se) or absence of disodium selenite pentahydrate (-Se). The antimutagenicity of MRS(+Se) extract was higher than that of MRS(-Se) extract. Selenium enhanced also the antimutagenic effect of both live and killed cells of E. faecium M-74, respectively. The live bacteria decreased the mutagenicity of selected substances more than killed cells. Synergic activity of selenium with the bacterium was also manifested.

Antimutagenic Agents↗
PubMed2006

Four butenolides are novel cytotoxic compounds isolated from the marine-derived bacterium, Streptoverticillium luteoverticillatum 11014.

Four known butenolides were isolated from the ethyl acetate extracts of the culture broth of the marine-derived bacterium, Streptoverticillium luteoverticillatum, by bioassay-guided fractionation. The structures were identified on the basis of spectral data. The absolute configuration of compound (1) was determined by CD spectrum for the first time. Compounds 1-4 showed in vitro cytotoxicity against the murine lymphoma P388 and human leukemia K562 cell lines. This is the first report on the isolation of butenolides from the marine bacterium, Streptoverticillium luteoverticillatum, and their cytotoxic activities.

Animals↗
PubMed1990

Metabolism of selenium in a selenium-dependent bacterium.

A selenium-dependent Bacillus sp. is able to grow well up to 3% sodium selenite-containing media. The bacterium completely failed to grow on media devoid of selenium. The presence of selenium in the growth media increased the bacterial contents of proteins, carbohydrates, and lipids. The highest quantities of amino acids were detected at 2% sodium selenite-containing media. The bacterium metabolized selenite into several protein selenoamino acids such as selenomethionine and selenocysteine/selenocystine, as well as nonprotein selenoamino acids, such as selenocystathionine. Several phosphoamino acids were detected in the presence of elevated levels of selenium. The synthesized protein seems not to be affected by the presence of selenium.

Amino Acids↗
PubMed1990

Mobilization of selenium by a selenium-dependent bacterium.

A selenium-dependent bacterium, Bacillus sp., failed to grow on selenium-free media. However, it is able to grow at high concentrations of sodium selenite containing media up to 3% (w/v). It accumulated extraordinary high quantities of selenium, 432 ppm/mL. The bacterium generated the transformation of inorganic selenium into volatile selenium form(s) into the atmosphere. The biological release of volatile selenium basically depended on several factors: incubation temperature, pH, incubation periods, and substrate concentration. Maximal quantity of the volatile selenium form was obtained at 30 degrees C, pH 7, and 1% (w/v) sodium selenite.

Bacillus↗
PubMed1997

Comparative analysis of Embden-Meyerhof and Entner-Doudoroff glycolytic pathways in hyperthermophilic archaea and the bacterium Thermotoga.

The Embden-Meyerhof (EM) or Entner-Doudoroff (ED) pathways of sugar degradation were analyzed in representative species of the hyperthermophilic archaeal genera Thermococcus, Desulfurococcus, Thermoproteus, and Sulfolobus, and in the hyperthermophilic (eu)bacterial genus Thermotoga. The analyses included (1) determination of 13C-labeling patterns by 1H- and 13C-NMR spectroscopy of fermentation products derived from pyruvate after fermentation of specifically 13C-labeled glucose by cell suspensions, (2) identification of intermediates of sugar degradation after conversion of 14C-labeled glucose by cell extracts, and (3) measurements of enzyme activities in cell extracts. Thermococcus celer and Thermococcus litoralis fermented 13C-glucose to acetate and alanine via a modified EM pathway (100%). This modification involves ADP-dependent hexokinase, 6-phosphofructokinase, and glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (GAP:FdOR). Desulfurococcus amylolyticus fermented 13C-glucose to acetate via a modified EM pathway in which GAP:FdOR replaces GAP-DH/phosphoglycerate kinase. Thermoproteus tenax fermented 13C-glucose to low amounts of acetate and alanine via simultaneous operation of the EM pathway (85%) and the ED pathway (15%). Aerobic Sulfolobus acidocaldarius fermented 13C-labeled glucose to low amounts of acetate and alanine exclusively via the ED pathway. The anaerobic (eu)bacterium Thermotoga maritima fermented 13C-glucose to acetate and lactate via the EM pathway (85%) and the ED pathway (15%). Cell extracts contained glucose-6-phosphate dehydrogenase and 2-keto-3-deoxy-6-phosphogluconate aldolase, key enzymes of the conventional phosphorylated ED pathway, and, as reported previously, all enzymes of the conventional EM pathway. In conclusion, glucose was degraded by hyperthermophilic archaea to pyruvate either via modified EM pathways with different types of hexose kinases and GAP-oxidizing enzymes, by the nonphosphorylated ED pathway, or by a combination of both pathways. In contrast, glucose catabolism in the hyperthermophilic (eu)bacterium Thermotoga involves the conventional forms of the EM and ED pathways. The data are in accordance with various previous reports.

Archaea↗
PubMed1999

Metabolism of L-phenylalanine and L-tyrosine by the phototrophic bacterium Rhodobacter capsulatus.

The phototrophic bacterium Rhodobacter capsulatus utilizes the aromatic amino acids L-phenylalanine and L-tyrosine as nitrogen source. L-Phenylalanine is hydroxylated to L-tyrosine, which is further converted into p-hydroxyphenyl pyruvate (pHPP) by a transamination reaction. The bacterium is unable to grow at the expense of these amino acids as the sole carbon source, although it is able to degrade them to homogentisate, probably by unspecific hydroxylation reactions. Metabolization of L-phenylalanine or L-tyrosine as nitrogen source requires phototrophic growth conditions and does not produce free ammonium inside the cells. A low aminotransferase activity with 2-oxoglutarate and L-tyrosine as substrates can be detected in crude extracts of R. capsulatus. Uptake of both amino acids by R. capsulatus was completely inhibited by ammonium addition, which also prevents aminotransferase induction.

Chromatography, High Pressure Liquid↗
PubMed1999

Transcriptional activity at supraoptimal temperature of growth in the antarctic psychrotrophic bacterium Pseudomonas syringae.

Transcriptional activity was monitored in cells of the Antarctic psychrotrophic bacterium Pseudomonas syringae (Lz4W), which does not grow above 30 degrees C. It was observed that the bacterium was capable of synthesising RNA at a temperature range of 0-37 degrees C, both in vitro and in vivo. The net incorporation of the radioactive precursor, [3H]uridine, into RNA was found to be affected at 37 degrees C. A pulse-chase experiment following a 32P labeling of RNA in vivo indicated that the ribosomal RNAs (rRNAs) degrade faster at and above 30 degrees C. It was also found that the increased ribonuclease (RNase) activity at high temperature might be responsible for this degradation. The attack on ribosomal RNAs by RNase took place after their assembly into ribosomal particles. It is suggested that the degradation of rRNAs at supraoptimal temperatures might be a detrimental factor for growth above 30 degrees C.

Animals↗
PubMed2004

The bacterium Xenorhabdus nematophila inhibits phospholipases A2 from insect, prokaryote, and vertebrate sources.

The bacterium, Xenorhabdus nematophila, is a virulent insect pathogen. Part of its pathogenicity is due to impairing cellular immunity by blocking biosynthesis of eicosanoids, the major recognized signal transduction system in insect cellular immunity. X. nematophila inhibits the first step in eicosanoid biosynthesis, phospholipase A(2) (PLA(2)). Here we report that the bacterium inhibits PLA(2) from two insect immune tissues, hemocytes and fat body, as well as PLA(2)s selected to represent a wide range of organisms, including prokaryotes, insects, reptiles, and mammals. Our finding on a bacterial inhibitor of PLA(2) activity contributes new insight into the chemical ecology of microbe-host interactions, which usually involve actions rather than inhibitors of PLA(2)s.

Animals↗
PubMed2003

Methanol utilization by a novel thermophilic homoacetogenic bacterium, Moorella mulderi sp. nov., isolated from a bioreactor.

A thermophilic, anaerobic, spore-forming bacterium (strain TMS) was isolated from a thermophilic bioreactor operated at 65 degrees C with methanol as the energy source. Cells were gram-positive straight rods, 0.4-0.6 microm x 2-8 microm, growing as single cells or in pairs. The temperature range for growth was 40-70 degrees C with an optimum at 65 degrees C. Growth was observed from pH 5.5 to 8.5, and the optimum pH was around 7. The salinity range for growth was 0-45 g NaCl l(-1 )with an optimum at 10 g l(-1). The isolate was able to grow on methanol, H(2)-CO(2 )(80/20%, v/v), formate, lactate, pyruvate, glucose, fructose, cellobiose and pectin. The bacterium reduced thiosulfate to sulfide. The G+C content of the DNA was 53 mol%. Comparison of 16S rRNA genes revealed that strain TMS is related to Moorella glycerini (96%, sequence similarity), Moorella thermoacetica (92%) and Moorella thermoautotrophica (92%). On the basis of physiological and phylogenetic differences, strain TMS is proposed as a new species within the genus Moorella, Moorella mulderi sp. nov. (=DSM 14980, =ATCC BAA-608).

Acetates↗
PubMed2003

Characterization of a new keratinolytic bacterium that completely degrades native feather keratin.

A novel feather-degrading microorganism was isolated from poultry waste, producing a high keratinolytic activity when cultured on broth containing native feather. Complete feather degradation was achieved during cultivation. The bacterium presents potential use for biotechnological processes involving keratin hydrolysis. Chryseobacterium sp. strain kr6 was identified based on morphological and biochemical tests and 16S rRNA sequencing. The bacterium presented optimum growth at pH 8.0 and 30 degrees C; under these conditions, maximum feather-degrading activity was also achieved. Maximum keratinase production was reached at 25 degrees C, while concentration of soluble protein was similar at both 25 and 30 degrees C. Reduction of disulfide bridges was also observed, increasing with cultivation time. The keratinase of strain kr6 was active on azokeratin and azocasein as substrates, and presented optimum pH and temperature of 7.5 and 55 degrees C, respectively. The keratinase activity was inhibited by 1,10-phenanthroline, EDTA, Hg(2+), and Cu(2+) and stimulated by Ca(2+).

Animals↗
PubMed2004

Heterologous overexpression of quorum-sensing regulators to study cell-density-dependent phenotypes in a symbiotic plant bacterium Mesorhizobium huakuii.

Quorum-sensing is widespread among many prokaryotic lineages. In order to investigate quorum regulation in the plant bacterium Mesorhizobium huakuii which produces an N-acyl homoserine lactone (AHL) quorum signal, the Agrobacterium quorum-sensing regulator TraR was heterologously expressed in this bacterium. The resulting strains showed reduced AHL production in the supernatant compared to wild-type, but similar intracellular levels of AHLs were detected, suggesting that M. huakuii AHLs can be bound to intracellular TraR proteins and thus become unavailable for its own quorum systems. M. huakuii overexpressing TraR formed thinner biofilms than the wild-type, suggesting a role played by quorum-sensing in biofilm formation.

4-Butyrolactone↗