title: Isolation and characterization of a thermophilic, obligately anaerobic and heterotrophic marine Chloroflexi bacterium from a Chloroflexi-dominated microbial community associated with a Japanese shallow hydrothermal system, and proposal for Thermomarinilinea lacunofontalis gen. nov., sp. nov.
abstract: A novel marine thermophilic and heterotrophic Anaerolineae bacterium in the phylum Chloroflexi, strain SW7(T), was isolated from an in situ colonization system deployed in the main hydrothermal vent of the Taketomi submarine hot spring field located on the southern part of Yaeyama Archipelago, Japan. The microbial community associated with the hydrothermal vent was predominated by thermophilic heterotrophs such as Thermococcaceae and Anaerolineae, and the next dominant population was thermophilic sulfur oxidizers. Both aerobic and anaerobic hydrogenotrophs including methanogens were detected as minor populations. During the culture-dependent viable count analysis in this study, an Anaerolineae strain SW7(T) was isolated from an enrichment culture at a high dilution rate. Strain SW7(T) was an obligately anaerobic heterotroph that grew with fermentation and had non-motile thin rods 3.5-16.5 μm in length and 0.2 μm in width constituting multicellular filaments. Growth was observed between 37-65°C (optimum 60°C), pH 5.5-7.3 (optimum pH 6.0), and 0.5-3.5% (w/v) NaCl concentration (optimum 1.0%). Based on the physiological and phylogenetic features of a new isolate, we propose a new species representing a novel genus Thermomarinilinea: the type strain of Thermomarinilinea lacunofontalis sp. nov., is SW7(T) (=JCM15506(T)=KCTC5908(T)).
authors.affiliation: Subsurface Geobiology & Advanced Research Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology, 2–15 Natsushima-cho, Yokosuka 237–0061, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Nunoura
authors.forename: Miho
authors.initials: M
authors.lastname: Hirai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kazama
authors.forename: Hiroko
authors.initials: H
authors.lastname: Makita
authors.forename: Hisako
authors.initials: H
authors.lastname: Hirayama
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Furushima
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Imachi
authors.forename: Ken
authors.initials: K
authors.lastname: Takai
mesh_terms: D000693:Anaerobiosis; D015373:Bacterial Typing Techniques; D041862:Chloroflexi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D052836:Heterotrophic Processes; D006863:Hydrogen-Ion Concentration; D060086:Hydrothermal Vents / Q000382:microbiology*; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride