| Deferribacter desulfuricans sp. nov., a novel sulfur-, nitrate- and arsenate-reducing thermophile isolated from a deep-sea hydrothermal vent.
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Takai K.,Kobayashi H.,Nealson KH.,Horikoshi K.
Int. J. Syst. Evol. Microbiol. 53 (2003) 839-46 [PMID: 12807210] Abstract
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| Abstract: A novel anaerobic, heterotrophic thermophile was isolated from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc, Japan. The cells were bent, flexible rods, with a single polar flagellum. Growth was observed between 40 and 70 degrees C (optimum temperature: 60-65 degrees C; doubling time, 40 min) and between pH 5.0 and 7.5(optimum pH 6.5). The isolate was a strictly anaerobic heterotroph capable of using complex organic compounds (yeast extract, tryptone, peptone, casein and Casamino acids), ethanol and various organic acids as energy and carbon sources. Hydrogen could serve as a supplementary energy source. Elemental sulfur (S(0)), nitrate or arsenate was required for growth as an electron acceptor. The G + C content of the genomic DNA was 38.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that isolate SSM1(T) is closely related to Deferribacter thermophilus BMA(T) (98.1%). However, the novel isolate could be clearly differentiated from D. thermophilus BMA(T) on the basis of its physiological and genetic properties. The name Deferribacter desulfuricans sp. nov. (type strain SSM1(T) = JCM 11476(T) = DSM 14783(T)) is proposed. |
| Evidence for the presence of thermophilic Fe(III)-reducing microorganisms in deep-sea hydrothermal vents at 13 degrees N (East Pacific Rise).
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Slobodkin A.,Campbell B.,Cary SC.,Bonch-Osmolovskaya E.,Jeanthon C.
FEMS Microbiol. Ecol. 36 (2001) 235-243 [PMID: 11451528] Abstract
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| Abstract: Microorganisms capable of dissimilatory Fe(III) reduction in the temperature range of 52-90 degrees C were enriched from outer and inner parts of chimney-like structures, tubes of the polychaetous annelid Alvinella sp., and hydrothermal fluids collected at 13 degrees N hydrothermal vent sites on the East Pacific Rise at a depth of 2650 m. Numbers of culturable Fe(III)-reducing thermophiles estimated by the serial dilution technique varied from 10 to 10(7) cells per cm(3) of sample. Phylogenetic analysis of bacterial and archaeal PCR-amplified 16S rDNA genes obtained from Fe(III)-reducing enrichments and separated by denaturing gradient gel electrophoresis revealed sequences related to Deferibacter, Thermotogales (Bacteria) and Thermococcus (Archaea) for which the capacity for Fe(III) reduction had been reported. This was confirmed by isolating a hyperthermophilic iron reducer that belongs to the genus Thermococcus. Other bacterial thermophiles found in the enrichments were related to so far uncultured members of the Clostridiaceae, and epsilon-subdivision of the Proteobacteria. |
