TY - JOUR
T1 - A multi-isotope study of deep-sea mussels at three different hydrothermal vent sites in the northwestern Pacific
AU - Naraoka, Hiroshi
AU - Naito, Taku
AU - Yamanaka, Toshiro
AU - Tsunogai, Urumu
AU - Fujikura, Katsunori
N1 - Funding Information:
We are grateful to crew members of Shinkai 2000 for their collection of two B. platifrons mussels from the Hatoma seamount and Daiyon-Yonaguni knoll, and Dr. Y. Chikaraishi for his support of compound-specific hydrogen isotope analysis. Prof. J. Ishibashi is acknowledged for discussion on carbon isotope distributions of volatile gases around the hydrothermal vents. We thank Prof. S. R. Poulson for improving the manuscript. Anonymous reviewers and Prof. Bourdon are acknowledged for critical comments. This work was supported as a part of the “Archean Park Project” by a grant from the Special Coordination Fund of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT).
PY - 2008/9/30
Y1 - 2008/9/30
N2 - To investigate symbiotic bacterial ecosystems at different deep-sea hydrothermal systems in the northwestern Pacific, compound-specific carbon and hydrogen isotope analyses of lipid biomarkers have been performed in addition to bulk C, H, N, S and O isotope analyses on Bathymodiolus mussels from the Hatoma seamount (B. platifrons), the Daiyon-Yonaguni (Yonaguni) knoll (B. platifrons), and the Suiyo seamount (B. septemdierum). The two B. platifrons contain large amounts of diploptene, while no hopanoid is detected in B. septemdierum, suggesting that B. platifrons and B. septemdierum harbors methanotrophic and thiotrophic bacteria, respectively. In spite of the same symbiont, the large bulk δ13C difference between the Hatoma (- 44.8‰) and Yonaguni (- 24.5‰) mussels reflects isotopically distinct hydrothermal CH4 (Hatoma: ~ - 48‰, Yonaguni: ~ -26‰) as a carbon source. Fatty acids of the Hatoma and Yonaguni mussels are more enriched in D (- 144 to - 101‰) than the Suiyo mussel (- 265 to - 162‰), suggesting that D-depleted magmatic water or D-enriched hydrogen derived from CH4 could be a partial hydrogen source for methanotrophy or thiotrophy, respectively. Apparent positive correlations are observed between δ13C and δD of the bulk and biomarkers for each mussel due to similar biochemical processes during de novo synthesis. The compound-specific δ13C and δD variations have provided much information on not only distinct carbon and hydrogen sources but also the lipid synthesis with respect to different symbiotic bacterial ecosystems.
AB - To investigate symbiotic bacterial ecosystems at different deep-sea hydrothermal systems in the northwestern Pacific, compound-specific carbon and hydrogen isotope analyses of lipid biomarkers have been performed in addition to bulk C, H, N, S and O isotope analyses on Bathymodiolus mussels from the Hatoma seamount (B. platifrons), the Daiyon-Yonaguni (Yonaguni) knoll (B. platifrons), and the Suiyo seamount (B. septemdierum). The two B. platifrons contain large amounts of diploptene, while no hopanoid is detected in B. septemdierum, suggesting that B. platifrons and B. septemdierum harbors methanotrophic and thiotrophic bacteria, respectively. In spite of the same symbiont, the large bulk δ13C difference between the Hatoma (- 44.8‰) and Yonaguni (- 24.5‰) mussels reflects isotopically distinct hydrothermal CH4 (Hatoma: ~ - 48‰, Yonaguni: ~ -26‰) as a carbon source. Fatty acids of the Hatoma and Yonaguni mussels are more enriched in D (- 144 to - 101‰) than the Suiyo mussel (- 265 to - 162‰), suggesting that D-depleted magmatic water or D-enriched hydrogen derived from CH4 could be a partial hydrogen source for methanotrophy or thiotrophy, respectively. Apparent positive correlations are observed between δ13C and δD of the bulk and biomarkers for each mussel due to similar biochemical processes during de novo synthesis. The compound-specific δ13C and δD variations have provided much information on not only distinct carbon and hydrogen sources but also the lipid synthesis with respect to different symbiotic bacterial ecosystems.
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U2 - 10.1016/j.chemgeo.2008.05.015
DO - 10.1016/j.chemgeo.2008.05.015
M3 - Article
AN - SCOPUS:50449106899
SN - 0009-2541
VL - 255
SP - 25
EP - 32
JO - Chemical Geology
JF - Chemical Geology
IS - 1-2
ER -