19 resultados para sulfur bacterium
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Desulfovibrio sp. A2 is an anaerobic gram-negative sulfate-reducing bacterium with remarkable tolerance to copper. It was isolated from wastewater effluents of a zinc smelter at the Urals. Here, we report the 4.2-Mb draft genome sequence of Desulfovibrio sp. A2 and identify potential copper resistance mechanisms.
Resumo:
We have sequenced the genome of Desulfosporosinus sp. OT, a Gram-positive, acidophilic sulfate-reducing Firmicute isolated from copper tailing sediment in the Norilsk mining-smelting area in Northern Siberia, Russia. This represents the first sequenced genome of a Desulfosporosinus species. The genome has a size of 5.7 Mb and encodes 6,222 putative proteins.
Resumo:
Homeopathic preparations are used in homeopathy and anthroposophic medicine. Although there is evidence of effectiveness in several clinical studies, including double-blinded randomized controlled trials, their nature and mode of action could not be explained with current scientific approaches yet. Several physical methods have already been applied to investigate homeopathic preparations but it is yet unclear which methods are best suited to identify characteristic physicochemical properties of homeopathic preparations. The aim of this study was to investigate homeopathic preparations with UV-spectroscopy. In a blinded, randomized, controlled experiment homeopathic preparations of copper sulfate (CuSO(4); 11c-30c), quartz (SiO(2); 10c-30c, i.e., centesimal dilution steps) and sulfur (S; 11×-30×, i.e., decimal dilution steps) and controls (one-time succussed diluent) were investigated using UV-spectroscopy and tested for contamination by inductively coupled plasma mass spectrometry (ICP-MS). The UV transmission for homeopathic preparations of CuSO(4) preparations was significantly lower than in controls. The transmission seemed to be also lower for both SiO(2) and S, but not significant. The mean effect size (95% confidence interval) was similar for the homeopathic preparations: CuSO(4) (pooled data) 0.0544% (0.0260-0.0827%), SiO(2) 0.0323% (-0.0064% to 0.0710%) and S 0.0281% (-0.0520% to 0.1082%). UV transmission values of homeopathic preparations had a significantly higher variability compared to controls. In none of the samples the concentration of any element analyzed by ICP-MS exceeded 100 ppb. Lower transmission of UV light may indicate that homeopathic preparations are less structured or more dynamic than their succussed pure solvent.
Resumo:
Twenty coagulase-negative Staphylococcus strains displaying alpha-haemolysis (delta-haemolysin) on sheep-blood agar were isolated from the noses of different pigs in Switzerland. The strains were Gram-stain-positive, non-motile cocci, catalase-positive and coagulase-negative. Sequence analysis of the 16S rRNA gene, sodA, rpoB, dnaJ and hsp60 and phylogenetic characteristics revealed that the strains showed the closest relatedness to Staphylococcus microti CCM 4903(T) and Staphylococcus muscae DSM 7068(T). The strains can be differentiated from S. microti by the absence of mannose fermentation and arginine arylamidase and from S. muscae by the absence of beta-glucuronidase activity and production of alkaline phosphatase. The chosen type strain ARI 262(T) shared 20.1 and 31.9 % DNA relatedness with S. microti DSM 22147(T) and S. muscae CCM 4903(T), respectively, by DNA-DNA hybridization. iso-C(15 : 0), anteiso-C(15 : 0) and iso-C(17 : 0) were the most common fatty acids. Cell-wall structure analysis revealed the peptidoglycan type A3alpha l-Lys-Gly(2)-l-Ser-Gly (type A11.3). The presence of teichoic acid was determined by sequencing the N-acetyl-beta-d-mannosaminyltransferase gene tarA, which is involved in biosynthesis of ribitol teichoic acid. Menaquinone 7 (MK-7) was the predominant respiratory quinone. The G+C content of ARI 262(T) was 38.8 mol%. The isolated strains represent a novel species of the genus Staphylococcus, for which we propose the name Staphylococcus rostri sp. nov. The type strain is ARI 262(T) (=DSM 21968(T) =CCUG 57266(T)) and strain ARI 602 (=DSM 21969 =CCUG 57267) is a reference strain.
Resumo:
Homeopathic remedies are produced by potentising, that is, the serial logarithmic dilution and succussion of a mother tincture. Techniques like ultraviolet spectroscopy, nuclear magnetic resonance, calorimetry, or thermoluminescence have been used to investigate their physical properties. In this study, homeopathic centesimal (c) potencies (6c to 30c) of copper sulfate, Hypericum perforatum, and sulfur as well as succussed water controls were prepared. Samples of these preparations were exposed to external physical factors like heat, pressure, ultraviolet radiation, or electromagnetic fields to mimic possible everyday storage conditions. The median transmissions from 190nm to 340nm and 220nm to 340nm were determined by ultraviolet light spectroscopy on five measurement days distributed over several months. Transmissions of controls and potencies of sulfur differed significantly on two of five measurement days and after exposure to physical factors. Transmissions of potencies exposed to ultraviolet light and unexposed potencies of copper sulfate and Hypericum perforatum differed significantly. Potency levels 6c to 30c were also compared, and wavelike patterns of higher and lower transmissions were found. The Kruskal-Wallis test yielded significant differences for the potency levels of all three substances. Aiming at understanding the physical properties of homeopathic preparations, this study confirmed and expanded the findings of previous studies.
Resumo:
Quantitative meta-analyses of randomized clinical trials investigating the specific therapeutic efficacy of homeopathic remedies yielded statistically significant differences compared to placebo. Since the remedies used contained mostly only very low concentrations of pharmacologically active compounds, these effects cannot be accounted for within the framework of current pharmacology. Theories to explain clinical effects of homeopathic remedies are partially based upon changes in diluent structure. To investigate the latter, we measured for the first time high-field (600/500 MHz) 1H T1 and T2 nuclear magnetic resonance relaxation times of H2O in homeopathic preparations with concurrent contamination control by inductively coupled plasma mass spectrometry (ICP-MS). Homeopathic preparations of quartz (10c–30c, n = 21, corresponding to iterative dilutions of 100−10–100−30), sulfur (13x–30x, n = 18, 10−13–10−30), and copper sulfate (11c–30c, n = 20, 100−11–100−30) were compared to n = 10 independent controls each (analogously agitated dilution medium) in randomized and blinded experiments. In none of the samples, the concentration of any element analyzed by ICP-MS exceeded 10 ppb. In the first measurement series (600 MHz), there was a significant increase in T1 for all samples as a function of time, and there were no significant differences between homeopathic potencies and controls. In the second measurement series (500 MHz) 1 year after preparation, we observed statistically significant increased T1 relaxation times for homeopathic sulfur preparations compared to controls. Fifteen out of 18 correlations between sample triplicates were higher for controls than for homeopathic preparations. No conclusive explanation for these phenomena can be given at present. Possible hypotheses involve differential leaching from the measurement vessel walls or a change in water molecule dynamics, i.e., in rotational correlation time and/or diffusion. Homeopathic preparations thus may exhibit specific physicochemical properties that need to be determined in detail in future investigations.
Resumo:
Dermatophilus-like bacteria were observed in histological examinations of samples of diseased foot skin from greater flamingos (Phoenicopterus roseus) living in zoological gardens in Switzerland. When grown on TSA-SB containing polymyxin B, the bacteria isolated from these skin samples formed hyphae, as is typical for Dermatophilus congolensis, but these bacteria were non-haemolytic. The closest relatives based on 16S rRNA gene sequences were the two members of the genus Arsenicicoccus, Arsenicicoccus bolidensis and Arsenicicoccus piscis. A representative of the isolated strains shared 34.3 % DNA-DNA relatedness with the type strain of A. bolidensis, 32.3 % with the type strain of A. piscis and 34.5 % with the type strain of D. congolensis, demonstrating that these strains do not belong to any of these species. The phenotypic characteristics differed from those of members of the genus Arsenicicoccus as well as from those of D. congolensis. The G+C content of strain KM 894/11(T) was 71.6 mol%. The most abundant fatty acids were iso-C15 : 0, summed feature 3 (including C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω9c. MK-8(H4) was the predominant menaquinone. Cell-wall structure analysis revealed that the peptidoglycan type was A3γ ll-Dpm-Gly (type A41.1). Based on genotypic and chemotaxonomic characteristics, the isolated strains represent a novel species within the genus Arsenicicoccus, for which the name Arsenicicoccus dermatophilus sp. nov. is proposed. The type strain is KM 894/11(T) ( = DSM 25571(T) = CCUG 62181(T) = CCOS 690(T)), and strain KM 1/12 ( = DSM 25572 = CCUG 62182 = CCOS 691) is a reference strain.
Resumo:
Segmented filamentous bacterium (SFB) is a symbiont that drives postnatal maturation of gut adaptive immune responses. In contrast to nonpathogenic E. coli, SFB stimulated vigorous development of Peyer's patches germinal centers but paradoxically induced only a low frequency of specific immunoglobulin A (IgA)-secreting cells with delayed accumulation of somatic mutations. Moreover, blocking Peyer's patch development abolished IgA responses to E. coli, but not to SFB. Indeed, SFB stimulated the postnatal development of isolated lymphoid follicles and tertiary lymphoid tissue, which substituted for Peyer's patches as inductive sites for intestinal IgA and SFB-specific T helper 17 (Th17) cell responses. Strikingly, in mice depleted of gut organized lymphoid tissue, SFB still induced a substantial but nonspecific intestinal Th17 cell response. These results demonstrate that SFB has the remarkable capacity to induce and stimulate multiple types of intestinal lymphoid tissues that cooperate to generate potent IgA and Th17 cell responses displaying only limited target specificity.
Resumo:
Chlorophyll (chl) breakdown during senescence is an integral part of plant development and leads to the accumulation of colorless catabolites. The loss of green pigment is due to an oxygenolytic opening of the porphyrin macrocycle of pheophorbide (pheide) a followed by a reduction to yield a fluorescent chl catabolite. This step is comprised of the interaction of two enzymes, pheide a oxygenase (PaO) and red chl catabolite reductase. PaO activity is found only during senescence, hence PaO seems to be a key regulator of chl catabolism. Whereas red chl catabolite reductase has been cloned, the nature of PaO has remained elusive. Here we report on the identification of the PaO gene of Arabidopsis thaliana (AtPaO). AtPaO is a Rieske-type iron–sulfur cluster-containing enzyme that is identical to Arabidopsis accelerated cell death 1 and homologous to lethal leaf spot 1 (LLS1) of maize. Biochemical properties of recombinant AtPaO were identical to PaO isolated from a natural source. Production of fluorescent chl catabolite-1 required ferredoxin as an electron source and both substrates, pheide a and molecular oxygen. By using a maize lls1 mutant, the in vivo function of PaO, i.e., degradation of pheide a during senescence, could be confirmed. Thus, lls1 leaves stayed green during dark incubation and accumulated pheide a that caused a light-dependent lesion mimic phenotype. Whereas proteins were degraded similarly in wild type and lls1, a chl-binding protein was selectively retained in the mutant. PaO expression correlated positively with senescence, but the enzyme appeared to be post-translationally regulated as well.
A perturbed parameter model ensemble to investigate Mt. Pinatubo's 1991 initial sulfur mass emission