Microbial community stratification controlled by the subseafloor fluid flow and geothermal gradient at the Iheya North hydrothermal field in the Mid-Okinawa Trough (Integrated Ocean Drilling Program Expedition 331)

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doi: 10.1128/AEM.01741-14
Author(s): Yanagawa, Katsumori; Breuker, Anja; Schippers, Axel; Nishizawa, Manabu; Ijiri, Akira; Hirai, Miho; Takaki, Yoshihiro; Sunamura, Michinari; Urabe, Tetsuro; Nunoura, Takuro; Takai, Ken
Author Affiliation(s): Primary:
Japan Agency for Marine-Earth Science and Technology, Department of Subsurface Geobiological Analysis and Research, Yokosuka, Japan
Federal Institute for Geosciences and Natural Resources, Germany
University of Tokyo, Japan
Volume Title: Applied and Environmental Microbiology
Source: Applied and Environmental Microbiology, 80(19), p.6126-6135. Publisher: American Society for Microbiology, Washington, DC, United States. ISSN: 0099-2240 CODEN: AEMIDF
Note: In English. 71 refs.; illus.
Summary: The impacts of lithologic structure and geothermal gradient on subseafloor microbial communities were investigated at a marginal site of the Iheya North hydrothermal field in the Mid-Okinawa Trough. Subsurface marine sediments composed of hemipelagic muds and volcaniclastic deposits were recovered through a depth of 151 m below the seafloor at site C0017 during Integrated Ocean Drilling Program Expedition 331. Microbial communities inferred from 16S rRNA gene clone sequencing in low-temperature hemipelagic sediments were mainly composed of members of the Chloroflexi and deep-sea archaeal group. In contrast, 16S rRNA gene sequences of marine group I Thaumarchaeota dominated the microbial phylotype communities in the coarse-grained pumiceous gravels interbedded between the hemipelagic sediments. Based on the physical properties of sediments such as temperature and permeability, the porewater chemistry, and the microbial phylotype compositions, the shift in the physical properties of the sediments is suggested to induce a potential subseafloor recharging flow of oxygenated seawater in the permeable zone, leading to the generation of variable chemical environments and microbial communities in the subseafloor habitats. In addition, the deepest section of sediments under high-temperature conditions (∼90°C) harbored the sequences of an uncultivated archaeal lineage of hot water crenarchaeotic group IV that may be associated with the high-temperature hydrothermal fluid flow. These results indicate that the subseafloor microbial community compositions and functions at the marginal site of the hydrothermal field are highly affected by the complex fluid flow structure, such as recharging seawater and underlying hydrothermal fluids, coupled with the lithologic transition of sediments.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Chemical composition; Expedition 331; Fluid flow; Geochemistry; Hydrology; IODP Site C0017; Iheya North hydrothermal field; Integrated Ocean Drilling Program; Marine sediments; Microorganisms; North Pacific; Northwest Pacific; Nucleic acids; Okinawa Trough; Pacific Ocean; RNA; Sediments; West Pacific
Coordinates: N274730 N274730 E1265443 E1265443
Record ID: 2018049493
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