title: Palaeococcus pacificus sp. nov., an archaeon from deep-sea hydrothermal sediment.
abstract: A hyperthermophilic, anaerobic, piezophilic archaeon (strain DY20341(T)) was isolated from a sediment sample collected from an East Pacific Ocean hydrothermal field (1° 37' S 102° 45' W) at a depth of 2737 m. The cells were irregular cocci, 0.8-1.5 µm in diameter. Growth was observed between 50 and 90 °C (optimum 80 °C), pH 5.0 and 8.0 (optimum pH 7.0), 1% and 7% (w/v) sea salts (Sigma, optimum 3%), 1% and 4% (w/v) NaCl (optimum 3%) and 0.1 and 80 MPa (optimum 30 MPa). The minimum doubling time was 66 min at 30 MPa and 80 °C. The isolate was an obligate chemoorganoheterotroph, capable of utilizing complex organic compounds and organic acids including yeast extract, peptone, tryptone, casein, starch, Casamino acids, citrate, lactate, acetate, fumarate, propanoate and pyruvate for growth. It was strictly anaerobic and facultatively dependent on elemental sulfur or sulfate as electron acceptors, but did not reduce sulfite, thiosulfate, Fe(III) or nitrate. The presence of elemental sulfur enhanced growth. The G+C content of the genomic DNA was 43.6 ± 1 mol%. 16S rRNA gene sequence analysis revealed that the closest relative of the isolated organism was Palaeococcus ferrophilus DMJ(T) (95.7% 16S rRNA gene similarity). On the basis of its physiological properties and phylogenetic analyses, the isolate is considered to represent a novel species, for which the name Palaeococcus pacificus sp. nov. is proposed. The type strain is strain DY20341(T) (=JCM 17873(T)=DSM 24777(T)).
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography SOA, Xiamen, Fujian 361005, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography SOA, Xiamen, Fujian 361005, PR China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography SOA, Xiamen, Fujian 361005, PR China.
authors.forename: Lijing
authors.initials: L
authors.lastname: Jiang
authors.affiliation: CNRS, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Institut Universitaire Européen de la Mer (IUEM), Place Nicolas Copernic, 29280 Plouzané, France.|Université de Bretagne Occidentale, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Institut Universitaire Européen de la Mer (IUEM), Place Nicolas Copernic, 29280 Plouzané, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Alain
authors.affiliation: CNRS, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Institut Universitaire Européen de la Mer (IUEM), Place Nicolas Copernic, 29280 Plouzané, France.|Université de Bretagne Occidentale, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Institut Universitaire Européen de la Mer (IUEM), Place Nicolas Copernic, 29280 Plouzané, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Jebbar
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography SOA, Xiamen, Fujian 361005, PR China.
authors.forename: Zongze
authors.initials: Z
authors.lastname: Shao
mesh_terms: D001482:Base Composition; D019641:DNA, Archaeal / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D060086:Hydrothermal Vents / Q000382:microbiology*; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D019710:Thermococcaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D019641:DNA, Archaeal; D012336:RNA, Ribosomal, 16S