HR: 0800h
AN: V41B-1378    [Abstracts]
TI: Diversity and distribution of microbes in deep-sea sub-vent systems, using newly designed in situ growth chambers
AU: * Higashi, Y
EM: y-higashi@aist.go.jp
AF: Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8566 Japan
AU: Sunamura, M
EM: sunamura@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetary Sciences, University of Tokyo, Hongo, Bunkyo,, Tokyo, 113-0033 Japan
AU: Utsumi, M
EM: utsumi@bsys.tsukuba.ac.jp
AF: University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8572 Japan
AU: Urabe, T
EM: urabe@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetary Sciences, University of Tokyo, Hongo, Bunkyo,, Tokyo, 113-0033 Japan
AU: Maruyama, A
EM: maruyama-aki@aist.go.jp
AF: Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8566 Japan
AB: Subsurface of deep-sea hydrothermal vent environments is one of the most difficult fields on the Earth to approach and collect reliable samples for microbiological study. In our Archaean Park project, we developed in situ incubation instruments to directly collect microbes from sub-vent fields through a drilled borehole. After excavation using a portable submarine driller (BMS) around deep-sea hydrothermal vents in the Suiyo Seamount on the Izu-Bonin Arc (2001, 2002) and the South Mariana (2003), microbial diversity was examined in samples collected from the boreholes, as well as natural vents, using catheter- and column-type in situ growth chambers. In the catheter samples collected from the Suiyo Seamount, several novel phylotypes of microbial SSU rRNA genes were assigned within epsilon-Proteobacteria and hyperthermophile-related Euryarchaea groups. The former novel epsilon group (SSSV-BE1) was also detected in the South Mariana, but they only appeared in the catheter samples collected just below the venting seafloor. These suggest that the group must be significant in warm, shallow and microaerobic sub-vent layers over the sea, at least in the northwest Pacific Ocean. The column-type in situ growth chamber was specially designed for creating and maintaining physico-chemical gradients in a ca. 40-cm-long column situated on an active vent. In Suiyo Seamount samples (vent temp.: ca. 30-100 degree C), a unique vertical profile was found in the diversity of Archaea. At the column bottom, most of the clones were assigned to be members within the lithoautotrophic thermophilic Ignicoccus, while heterotrophic thermophilic Thermococcus were abundant at the column top. Similar vertical profile has also been appeared in the column samples from the South Mariana. Further quantitative population analysis is now under going using these samples. Our approach to the sub-vent biosphere by the combination of drilling and in situ incubation is almost sure to give us important clues to find and simulate microbial community members in such extreme but different subsurface conditions.
DE: 4815 Ecosystems, structure and dynamics
DE: 4803 Bacteria
DE: 1794 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting