@article{IjiriInagakiKuboetal.2018,
  author    = {Ijiri, Akira and Inagaki, Fumio and Kubo, Yusuke and Adhikari, Rishi Ram and Hattori, Shohei and Hoshino, Tatsuhiko and Imachi, Hiroyuki and Kawagucci, Shinsuke and Morono, Yuki and Ohtomo, Yoko and Ono, Shuhei and Sakai, Sanae and Takai, Ken and Toki, Tomohiro and Wang, David T. and Yoshinaga, Marcos Y. and Arnold, Gail L. and Ashi, Juichiro and Case, David H. and Feseker, Tomas and Hinrichs, Kai-Uwe and Ikegawa, Yojiro and Ikehara, Minoru and Kallmeyer, Jens and Kumagai, Hidenori and Lever, Mark Alexander and Morita, Sumito and Nakamura, Ko-ichi and Nakamura, Yuki and Nishizawa, Manabu and Orphan, Victoria J. and Roy, Hans and Schmidt, Frauke and Tani, Atsushi and Tanikawa, Wataru and Terada, Takeshi and Tomaru, Hitoshi and Tsuji, Takeshi and Tsunogai, Urumu and Yamaguchi, Yasuhiko T. and Yoshida, Naohiro},
  title     = {Deep-biosphere methane production stimulated by geofluids in the Nankai accretionary complex},
  series = {Science Advances},
  volume    = {4},
  journal   = {Science Advances},
  number    = {6},
  publisher = {American Assoc. for the Advancement of Science},
  address   = {Washington},
  issn      = {2375-2548},
  doi       = {10.1126/sciadv.aao4631},
  pages     = {15},
  year      = {2018},
  language  = {en}
}
@misc{IjiriInagakiKuboetal.2018,
  author    = {Ijiri, Akira and Inagaki, Fumio and Kubo, Yusuke and Adhikari, Rishi Ram and Hattori, Shohei and Hoshino, Tatsuhiko and Imachi, Hiroyuki and Kawagucci, Shinsuke and Morono, Yuki and Ohtomo, Yoko and Ono, Shuhei and Sakai, Sanae and Takai, Ken and Toki, Tomohiro and Wang, David T. and Yoshinaga, Marcos Y. and Arnold, Gail L. and Ashi, Juichiro and Case, David H. and Feseker, Tomas and Hinrichs, Kai-Uwe and Ikegawa, Yojiro and Ikehara, Minoru and Kallmeyer, Jens and Kumagai, Hidenori and Lever, Mark Alexander and Morita, Sumito and Nakamura, Ko-ichi and Nakamura, Yuki and Nishizawa, Manabu and Orphan, Victoria J. and R{\o}y, Hans and Schmidt, Frauke and Tani, Atsushi and Tanikawa, Wataru and Terada, Takeshi and Tomaru, Hitoshi and Tsuji, Takeshi and Tsunogai, Urumu and Yamaguchi, Yasuhiko T. and Yoshida, Naohiro},
  title     = {Deep-biosphere methane production stimulated by geofluids in the Nankai accretionary complex},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {802},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42700},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427002},
  pages     = {16},
  year      = {2018},
  abstract  = {Microbial life inhabiting subseafloor sediments plays an important role in Earth's carbon cycle. However, the impact of geodynamic processes on the distributions and carbon-cycling activities of subseafloor life remains poorly constrained. We explore a submarine mud volcano of the Nankai accretionary complex by drilling down to 200 m below the summit. Stable isotopic compositions of water and carbon compounds, including clumped methane isotopologues, suggest that ~90\% of methane is microbially produced at 16° to 30°C and 300 to 900 m below seafloor, corresponding to the basin bottom, where fluids in the accretionary prism are supplied via megasplay faults. Radiotracer experiments showed that relatively small microbial populations in deep mud volcano sediments (10 2 to 10 3 cells cm -3 ) include highly active hydrogenotrophic methanogens and acetogens. Our findings indicate that subduction-associated fluid migration has stimulated microbial activity in the mud reservoir and that mud volcanoes may contribute more substantially to the methane budget than previously estimated.},
  language  = {en}
}
@misc{AdhikariGlombitzaNickeletal.2016,
  author    = {Adhikari, Rishi Ram and Glombitza, Clemens and Nickel, Julia C. and Anderson, Chloe H. and Dunlea, Ann G. and Spivack, Arthur J. and Murray, Richard W. and D'Hondt, Steven and Kallmeyer, Jens},
  title     = {Hydrogen utilization potential in subsurface sediments},
  series = {Frontiers in microbiology},
  journal   = {Frontiers in microbiology},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407678},
  pages     = {16},
  year      = {2016},
  abstract  = {Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material. We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i) increasing importance of fermentation in successively deeper biogeochemical zones and (ii) adaptation of H(2)ases to successively higher concentrations of H-2 in successively deeper zones.},
  language  = {en}
}