title: Sulfurihydrogenibium kristjanssonii sp. nov., a hydrogen- and sulfur-oxidizing thermophile isolated from a terrestrial Icelandic hot spring.
abstract: Three thermophilic, aerobic, hydrogen- and sulfur-oxidizing bacteria were isolated from an Icelandic hot spring near the town of Hveragerdi and share >99 % 16S rRNA gene sequence similarity. One of these isolates, designated strain I6628T, was selected for further characterization. Strain I6628T is a motile rod, 1.5-2.5 microm long and about 0.5 microm wide. Growth occurred between 40 and 73 degrees C (optimally at 68 degrees C), at pH 5.3-7.8 (optimally at pH 6.6) and at NaCl concentrations between 0 and 0.5 % (w/v). Strain I6628T grew with H2, S0 or S2O3(2-) as an electron donor with O2 (up to 25 %, v/v; optimally at 4-9 %) as the sole electron acceptor. CO2 and succinate were utilized as carbon sources but no organic compounds, including succinate, could be used as an energy source. The G+C content of the genomic DNA was determined to be 28.1 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain I6628T is a member of the genus Sulfurihydrogenibium, the closest cultivated relative being the recently described strain Sulfurihydrogenibium rodmanii UZ3-5T (98.2 % sequence similarity). On the basis of the physiology and phylogeny of this organism, strain I6628T represents a novel species of the genus Sulfurihydrogenibium, for which the name Sulfurihydrogenibium kristjanssonii sp. nov. is proposed. The type strain is I6628T (=DSM 19534T =OCM 901T =ATCC BAA-1535T).
authors.affiliation: Department of Biology, Portland State University, PO Box 751, Portland, OR 97207-0751, USA.
authors.forename: Gilberto E
authors.initials: GE
authors.lastname: Flores
authors.forename: Yitai
authors.initials: Y
authors.lastname: Liu
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferrera
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Beveridge
authors.forename: Anna-Louise
authors.initials: AL
authors.lastname: Reysenbach
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D020459:Genes, rRNA; D006091:Gram-Negative Chemolithotrophic Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D045482:Hot Springs / Q000382:microbiology*; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D007055:Iceland; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013455:Sulfur / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D006859:Hydrogen