Survival of Desulfotomaculum spores from estuarine sediments after serial autoclaving and high-temperature exposure (original) (raw)
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Frontiers in microbiology, 2013
Gram-positive spore-forming sulfate reducers and particularly members of the genus Desulfotomaculum are commonly found in the subsurface biosphere by culture based and molecular approaches. Due to their metabolic versatility and their ability to persist as endospores. Desulfotomaculum spp. are well-adapted for colonizing environments through a slow sedimentation process. Because of their ability to grow autotrophically (H2/CO2) and produce sulfide or acetate, these microorganisms may play key roles in deep lithoautotrophic microbial communities. Available data about Desulfotomaculum spp. and related species from studies carried out from deep freshwater lakes, marine sediments, oligotrophic and organic rich deep geological settings are discussed in this review.
International journal of systematic bacteriology, 1998
Two strains of moderately thermophilic bacteria, which reduce elemental sulfur to hydrogen sulfide, were isolated from volcanic sources in Kamchatka. Strain K-119T was obtained from a thermophilic microbial community associated with Thermothrix thiopara, and strain U-8T was isolated from a cyanobacterial mat inhabiting a sulfide-rich hot spring. Cells of both strains are short Gram-negative rods, motile with one polar flagellum (strain K-119T) or non-motile (strain U-8T). Both strains are obligate anaerobes, have temperature otima of 54-55 degrees C and pH optima of 6.9-7.2. Molecular hydrogen, acetate, fumarate, malate, pyruvate, lactate and long-chain saturated fatty acids served as growth substrates for both species; strain U-8T was also able to grow on propionate. All substrates were oxidized completely, H2S and CO2 being the only metabolic products. Elemental sulfur was obligately required for growth of strain K-119T, whereas strain U-8T was able to grow also with thiosulfate a...
3 Biotech, 2011
A strictly anaerobic moderately thermophilic bacterium, designated strain RH04-3(T) (T = type strain), was isolated from a red colored microbial mat that colonizes a Great Artesian Basin (GAB) bore well (Registered Number 17263) runoff channel at 66 °C. The cells of strain RH04-3(T) were straight to slightly curved, sporulating, Gram-positive rods (2.0-5.0 × 1.0 μm) that grew optimally at 50 °C (temperature growth range between 37 and 55 °C) and at pH 7 (pH growth range of 5.0 and 8.5). Growth was inhibited by NaCl concentrations ≥1.5% (w/v), and by chloramphenicol, streptomycin, tetracycline, penicillin and ampicillin. The strain utilized fructose, mannose, glycerol, lactate, pyruvate and H(2) in the presence of sulfate, and fermented pyruvate in the absence of sulfate. Strain RH04-3(T) reduced sulfate, sulfite, thiosulfate and elemental sulfur, but not nitrate, nitrite, iron(III), arsenate(V), vanadium(V) or cobalt(III) as terminal electron acceptors. The G + C content of DNA was ...
Extremophiles, 2007
A moderately thermophilic, sulphate-reducing bacterium, designated strain P6-2T, was isolated from a terrestrial hot spring located at a height of 2,500 m in the Andean region, Colombia (5°43′69″N, 73°6′10″W). Cells of strain P6-2T were rod-shaped, stained Gram-negative and were motile by means of a single polar flagellum. The strain grew lithotrophically with H2 as the electron donor and organotrophically on lactate, pyruvate, ethanol, malate, fumarate, n-propanol and succinate in the presence of sulphate as the terminal electron acceptor. Fumarate and pyruvate was fermented. Strain P6-2T grew optimally at 55°C (range 37–60°C), pH 6.6 (range 5.8–8.8) in the presence of 0.5% NaCl (range 0–4.5%) with lactate and sulphate and produced acetate, CO2 and H2S as the major end-products. Sulphate, sulphite and thiosulphate could be used as electron acceptors but not elemental sulphur or nitrate. The G + C content of the genomic DNA was 58.7 mol%. The 16S rRNA sequence analysis indicated that strain P6-2T was a member of the class Deltaproteobacteria, domain Bacteria with Desulfomicrobium baculatum being the closest relative (similarity value of 94%). Phylogeny of genes encoding α- and β-subunits of the dissimilatory sulphite reductase (dsrAB genes) supported its affiliation to members of the genus Desulfomicrobium. On the basis of this evidence, we propose to assign strain P6-2T as new species of the genus Desulfomicrobium, D. thermophilum sp. nov., with strain P6-2T as the type strain (= DSM 16697T = CCUG 49732T).
International Journal of Systematic and Evolutionary Microbiology, 2010
A thermophilic, sulfate-reducing bacterium, designated strain USBA-053T, was isolated from a terrestrial hot spring located at a height of 2500 m in the Colombian Andes (5° 45′ 33.29″ N 73° 6′ 49.89″ W), Colombia. Cells of strain USBA-053T were oval- to rod-shaped, Gram-negative and motile by means of a single polar flagellum. The strain grew autotrophically with H2 as the electron donor and heterotrophically on formate, propionate, butyrate, valerate, isovalerate, lactate, pyruvate, ethanol, glycerol, serine and hexadecanoic acid in the presence of sulfate as the terminal electron acceptor. The main end products from lactate degradation, in the presence of sulfate, were acetate, CO2 and H2S. Strain USBA-053T fermented pyruvate in the absence of sulfate and grew optimally at 57 °C (growth temperature ranged from 50 °C to 62 °C) and pH 6.8 (growth pH ranged from 5.7 to 7.7). The novel strain was slightly halophilic and grew in NaCl concentrations ranging from 5 to 30 g l−1, with an o...
The ISME journal, 2013
Patterns of microbial biogeography result from a combination of dispersal, speciation and extinction, yet individual contributions exerted by each of these mechanisms are difficult to isolate and distinguish. The influx of endospores of thermophilic microorganisms to cold marine sediments offers a natural model for investigating passive dispersal in the ocean. We investigated the activity, diversity and abundance of thermophilic endospore-forming sulfate-reducing bacteria (SRB) in Aarhus Bay by incubating pasteurized sediment between 28 and 85 °C, and by subsequent molecular diversity analyses of 16S rRNA and of the dissimilatory (bi)sulfite reductase (dsrAB) genes within the endospore-forming SRB genus Desulfotomaculum. The thermophilic Desulfotomaculum community in Aarhus Bay sediments consisted of at least 23 species-level 16S rRNA sequence phylotypes. In two cases, pairs of identical 16S rRNA and dsrAB sequences in Arctic surface sediment 3000 km away showed that the same phylot...