title: Persephonella marina gen. nov., sp. nov. and Persephonella guaymasensis sp. nov., two novel, thermophilic, hydrogen-oxidizing microaerophiles from deep-sea hydrothermal vents.
abstract: Two thermophilic, strictly chemolithoautotrophic, microaerophilic, hydrogen-oxidizing members of the Bacteria designated strain EX-H1T and strain EX-H2T were isolated from two separate deep-sea hydrothermal vent sites at 9 degrees N 104 degrees W in the Pacific Ocean and Guaymas Basin. The motile 2-4-microm-long rods were Gram-negative and non-sporulating. The temperature range for growth was between 55 and 80 degrees C for EX- H1T (optimum at 73 degrees C) and 55-75 C for EX-H2T (optimum at 70 C). Both strains grew fastest at 2.5% (w/v) NaCl and at pH 6, although growth was observed from pH 4.7 to pH 7.5. EX-H1T and EX-H2T were able to use elemental sulfur, thiosulfate or hydrogen as an electron donor, and oxygen (2-3%, v/v) or nitrate as an electron acceptor. EX-H1T was also able to use elemental sulfur as an electron acceptor. EX-H1T and EX-H2T further differed in their genomic G+C content (38.5 and 37.4 mol%, respectively) and 16S rRNA sequences (4% difference). Maximum-likelihood analysis of the 16S rRNA phylogeny placed both isolates within the Aquificales as a distinct lineage and showed them to be only about 85% similar to Aquifex pyrophilus. On the basis of phenotypic and phylogenetic characteristics, it is proposed that EX-H1T and EX-H2T belong to a new genus within the Aquificales, namely Persephonella gen. nov. It is further proposed that EX-H1T be named Persephonella marina sp. nov., the type species of the genus, and that EX-H2T be named Persephonella guaymasensis sp. nov., a second species in this genus.
authors.forename: D
authors.initials: D
authors.lastname: Götz
authors.forename: A
authors.initials: A
authors.lastname: Banta
authors.forename: T J
authors.initials: TJ
authors.lastname: Beveridge
authors.forename: A I
authors.initials: AI
authors.lastname: Rushdi
authors.forename: B R T
authors.initials: BRT
authors.lastname: Simoneit
authors.forename: A L
authors.initials: AL
authors.lastname: Reysenbach
mesh_terms: D001482:Base Composition; D004275:DNA, Ribosomal / Q000032:analysis; D006090:Gram-Negative Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D008800:Mexico; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010140:Pacific Ocean; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006859:Hydrogen