title: Sulfurihydrogenibium azorense, sp. nov., a thermophilic hydrogen-oxidizing microaerophile from terrestrial hot springs in the Azores.
abstract: Five hydrogen-oxidizing, thermophilic, strictly chemolithoautotrophic, microaerophilic strains, with similar (99-100%) 16S rRNA gene sequences were isolated from terrestrial hot springs at Furnas, São Miguel Island, Azores, Portugal. The strain, designated Az-Fu1T, was characterized. The motile, 0.9-2.0 microm rods were Gram-negative and non-sporulating. The temperature growth range was from 50 to 73 degrees C (optimum at 68 degrees C). The strains grew fastest in 0.1% (w/v) NaCl and at pH 6, although growth was observed from pH 5.5 to 7.0. Az-Fu1T can use elemental sulfur, sulfite, thiosulfate, ferrous iron or hydrogen as electron donors, and oxygen (0.2-9.0%, v/v) as electron acceptor. Az-Fu1T is also able to grow anaerobically, with elemental sulfur, arsenate and ferric iron as electron acceptors. The Az-Fu1T G+C content was 33.6 mol%. Maximum-likelihood analysis of the 16S rRNA phylogeny placed the isolate in a distinct lineage within the Aquificales, closely related to Sulfurihydrogenibium subterraneum (2.0% distant). The 16S rRNA gene of Az-Fu1T is 7.7% different from that of Persephonella marina and 6.8% different from Hydrogenothermus marinus. Based on the phenotypic and phylogenetic characteristics presented here, it is proposed that Az-Fu1T belongs to the recently described genus Sulfurihydrogenibium. It is further proposed that Az-Fu1T represents a new species, Sulfurihydrogenibium azorense.
authors.affiliation: Portland State University, Department of Biology, Portland, OR 97201, USA.
authors.forename: P
authors.initials: P
authors.lastname: Aguiar
authors.affiliation: Department of Microbiology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
authors.forename: T J
authors.initials: TJ
authors.lastname: Beveridge
authors.affiliation: Portland State University, Department of Biology, Portland, OR 97201, USA.
authors.forename: A-L
authors.initials: AL
authors.lastname: Reysenbach
mesh_terms: D001394:Azores; D006088:Gram-Negative Aerobic Bacteria / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D045482:Hot Springs / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011174:Portugal