Isolation and Characterization of a Thermophilic, Obligately Anaerobic and Heterotrophic Marine <i>Chloroflexi</i> Bacterium from a <i>Chloroflexi</i>-dominated Microbial Community Associated with a Japanese Shallow Hydrothermal System, and Proposal for <i>Thermomarinilinea lacunofontalis</i> gen. nov., sp. nov.

• DOI: 10.1264/jsme2.me12193
• Publication Date: 2013-05-10T22:57:34Z
• Authors: Takuro Nunoura; Miho Hirai; Masayuki Miyazaki; Hiromi Kazama; Hiroko Makita; Hisako Hirayama; Yasuo Furushima; Hiroyuki Yamamoto; Hiroyuki Imachi; Ken Takai
• Keywords: DNA, Bacterial; 0303 health sciences; Molecular Sequence Data; Temperature; Heterotrophic Processes; Articles; Chloroflexi; Sequence Analysis, DNA; Hydrogen-Ion Concentration; Sodium Chloride; DNA, Ribosomal; 6. Clean water; Bacterial Typing Techniques; 03 medical and health sciences; Hydrothermal Vents; Japan; RNA, Ribosomal, 16S; Cluster Analysis; Anaerobiosis; 14. Life underwater; Phylogeny

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)).