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Thiogranum longum gen. nov., sp. nov., an obligately chemolithoautotrophic, sulfur-oxidizing bacterium of the family Ectothiorhodospiraceae isolated from a deep-sea hydrothermal field, and an emended description of the genus Thiohalomonas

Mori, Koji, Suzuki, Ken-ichiro, Yamaguchi, Kaoru, Urabe, Tetsuro, Hanada, Satoshi
International journal of systematic and evolutionary microbiology 2015 v.65 no.Pt 1 pp. 235-241
Ectothiorhodospiraceae, bacteria, carbon dioxide, cell walls, fatty acids, nucleotide sequences, oxidation, oxygen, pH, phylogeny, quinones, ribosomal RNA, sodium chloride, sulfur, Pacific Ocean
A novel, obligately chemolithoautotrophic, sulfur-oxidizing bacterial strain, designated strain gps52 ᵀ, was isolated from a rock sample collected near the hydrothermal vents of the Suiyo Seamount in the Pacific Ocean. The cells possessed a Gram-stain-negative-type cell wall and contained menaquinone-8(H ₄) and menaquinone-9(H ₄) as respiratory quinones, and C ₁₆ : ₁ω7 c , C ₁₆ : ₀ and C ₁₈ : ₁ω7 c as major cellular fatty acids. Neither storage compounds nor extensive internal membranes were observed in the cells. Strain gps52 ᵀ grew using carbon dioxide fixation and oxidation of inorganic sulfur compounds with oxygen as electron acceptor. Optimal growth was observed at 32 °C, pH 6.5 and with 3 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain gps52 ᵀ belongs to the family Ectothiorhodospiraceae and is different from any other known bacteria, with sequence similarities of less than 93 %. Based on phenotypic and phylogenetic findings, the isolate is considered to represent a novel genus and species in the family Ectothiorhodospiraceae , and the name Thiogranum longum gen. nov., sp. nov. is proposed. The type strain is gps52 ᵀ (= NBRC 101260 ᵀ = DSM 19610 ᵀ). An emended description of the genus Thiohalomonas is also proposed.