title: Geomicrobiological exploration and characterization of a novel deep-sea hydrothermal system at the TOTO caldera in the Mariana Volcanic Arc.
abstract: Novel hydrothermal activities accompanying effluent white smokers and elemental sulfur chimney structures at the north-east lava dome of the TOTO caldera depression in the Mariana Volcanic Arc have been explored and characterized by geochemical and microbiological surveys. White smoker hydrothermal fluids were observed in the potential hydrothermal activity centre of the field and represented the maximal temperature of 170 degrees C and the lowest pH of 1.6. The chimney structures, all consisting of elemental sulfur (sulfur chimney), were also unique to the TOTO caldera hydrothermal field. Microbial community structures in a sulfur chimney and its formation hydrothermal fluid with a high concentration of hydrogen sulfide (15 mM) have been investigated by culture-dependent and -independent analyses. 16S rRNA gene clone analysis and fluorescence in situ hybridization (FISH) analysis revealed that epsilon-Proteobacteria dominated the microbial communities in the sulfur chimney structure and formed a dense microbial mat covering the sulfur chimney surface. Archaeal phylotypes were consistently minor components in the communities and related to the genera Thermococcus, Pyrodictium, Aeropyrum, and the uncultivated archaeal group of 'deep-sea hydrothermal vent euryarchaeotal group'. Cultivation analysis suggested that the chemolithoautotrophs might play a significant ecological role as primary producers utilizing gas and sulfur compounds provided from hydrothermal fluids.
authors.affiliation: Subground Animalcule Retrieval SUGAR Project, Japan Agency for Marine-Earth Science and Technology, JAMSTEC, Yokosuka 237-0061, Japan.
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Ken
authors.initials: K
authors.lastname: Takai
authors.forename: Yohey
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Hisako
authors.initials: H
authors.lastname: Hirayama
authors.forename: Uta
authors.initials: U
authors.lastname: Konno
authors.forename: Urumu
authors.initials: U
authors.lastname: Tsunogai
authors.forename: Koki
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D001105:Archaea / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D016000:Cluster Analysis; D020565:Epsilonproteobacteria / Q000235:genetics* / Q000254:growth & development; D005843:Geography; D006862:Hydrogen Sulfide / Q000032:analysis; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000032:analysis; D018707:Volcanic Eruptions; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D006862:Hydrogen Sulfide