title: Salinisphaera hydrothermalis sp. nov., a mesophilic, halotolerant, facultatively autotrophic, thiosulfate-oxidizing gammaproteobacterium from deep-sea hydrothermal vents, and emended description of the genus Salinisphaera.
abstract: A mesophilic, aerobic, facultatively chemolithoautotrophic bacterium, designated strain EPR70(T), was isolated from hydrothermal fluids from diffuse-flow vents on the East Pacific Rise at degrees 50' N 10 degrees 17' W. Cells were Gram-negative rods, approximately 0.8-1.0 microm long and 0.3-0.5 microm wide. Strain EPR70(T) grew at 20-40 degrees C (optimum 30-35 degrees C), 1-25 % NaCl (optimum 2.5 %) and pH 5.0-7.5 (optimum pH 5.5). The shortest generation time observed for strain EPR70(T) was 42 min. Growth occurred under aerobic chemolithoautotrophic conditions in the presence of thiosulfate and CO(2). Strain EPR70(T) grew heterotrophically with acetate or n-alkanes as sole carbon and energy sources, and in complex artificial seawater medium. Nitrate was not used as an electron acceptor. The G+C content of the genomic DNA was 64 mol%. Phylogenetic analysis of the 16S rRNA gene indicated that this organism is a member of the class Gammaproteobacteria, with Salinisphaera shabanensis E1L3A(T) as its closest relative (94 % sequence similarity). On the basis of phylogenetic analyses based on 16S rRNA, rbcL and alkB genes and physiological analysis, it is proposed that the organism represents a novel species within the genus Salinisphaera, for which the name Salinisphaera hydrothermalis sp. nov. is proposed. The type strain is EPR70(T) (=DSM 21483(T) =JCM 15514(T)).
authors.affiliation: Department of Biochemistry, Rutgers University, New Brunswick, NJ 08901, USA.
authors.forename: Melitza
authors.initials: M
authors.lastname: Crespo-Medina
authors.forename: Aspassia
authors.initials: A
authors.lastname: Chatziefthimiou
authors.forename: Ramaydalis
authors.initials: R
authors.lastname: Cruz-Matos
authors.forename: Ileana
authors.initials: I
authors.lastname: Pérez-Rodríguez
authors.forename: Tamar
authors.initials: T
authors.lastname: Barkay
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lutz
authors.forename: Valentin
authors.initials: V
authors.lastname: Starovoytov
authors.forename: Costantino
authors.initials: C
authors.lastname: Vetriani
mesh_terms: D001482:Base Composition; D052837:Chemoautotrophic Growth; D042926:Cytochrome P-450 CYP4A / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D020563:Gammaproteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism*; D013045:Species Specificity; D013885:Thiosulfates / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013885:Thiosulfates; D012965:Sodium Chloride; D042926:Cytochrome P-450 CYP4A; D012273:Ribulose-Bisphosphate Carboxylase