TY - JOUR
T1 - Microbial community in a sediment-hosted CO2 lake of the southern Okinawa Trough hydrothermal system
AU - Inagaki, Fumio
AU - Kuypers, Marcel M.M.
AU - Tsunogai, Urumu
AU - Ishibashi, Jun Ichiro
AU - Nakamura, Ko Ichi
AU - Treude, Tina
AU - Ohkubo, Satoru
AU - Nakaseama, Miwako
AU - Gena, Kaul
AU - Chiba, Hitoshi
AU - Hirayama, Hisako
AU - Munoura, Takuro
AU - Takai, Ken
AU - Jørgensen, Bo B.
AU - Horikoshi, Koki
AU - Boetius, Antje
PY - 2006/9/19
Y1 - 2006/9/19
N2 - Increasing levels of CO2 in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO2 disposal options are discussed, including injection into the deep ocean. Because the dissolution of CO2 in seawater will decrease ambient pH considerably, negative consequences for deep-water ecosystems have been predicted. Hence, ecosystems associated with natural CO2 reservoirs in the deep sea, and the dynamics of gaseous, liquid, and solid CO2 in such environments, are of great interest to science and society. We report here a biogeochemical and microbiological characterization of a microbial community inhabiting deep-sea sediments overlying a natural CO2 lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough. We found high abundances (>109 cm-3) of microbial cells in sediment pavements above the CO2 lake, decreasing to strikingly low cell numbers (107 cm-3) at the liquid CO2/CO 2-hydrate interface. The key groups in these sediments were as follows: (i) the anaerobic methanotrophic archaea ANME-2c and the Eel-2 group of Deltaproteobacteria and (ii) sulfur-metabolizing chemolithotrophs within the Gamma- and Epsilonproteobacteria. The detection of functional genes related to one-carbon assimilation and the presence of highly 13C-depleted archaeal and bacterial lipid biomarkers suggest that microorganisms assimilating CO2 and/or CH4 dominate the liquid CO2 and CO2-hydrate-bearing sediments. Clearly, the Yonaguni Knoll is an exceptional natural laboratory for the study of consequences of CO2 disposal as well as of natural CO2 reservoirs as potential microbial habitats on early Earth and other celestial bodies.
AB - Increasing levels of CO2 in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO2 disposal options are discussed, including injection into the deep ocean. Because the dissolution of CO2 in seawater will decrease ambient pH considerably, negative consequences for deep-water ecosystems have been predicted. Hence, ecosystems associated with natural CO2 reservoirs in the deep sea, and the dynamics of gaseous, liquid, and solid CO2 in such environments, are of great interest to science and society. We report here a biogeochemical and microbiological characterization of a microbial community inhabiting deep-sea sediments overlying a natural CO2 lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough. We found high abundances (>109 cm-3) of microbial cells in sediment pavements above the CO2 lake, decreasing to strikingly low cell numbers (107 cm-3) at the liquid CO2/CO 2-hydrate interface. The key groups in these sediments were as follows: (i) the anaerobic methanotrophic archaea ANME-2c and the Eel-2 group of Deltaproteobacteria and (ii) sulfur-metabolizing chemolithotrophs within the Gamma- and Epsilonproteobacteria. The detection of functional genes related to one-carbon assimilation and the presence of highly 13C-depleted archaeal and bacterial lipid biomarkers suggest that microorganisms assimilating CO2 and/or CH4 dominate the liquid CO2 and CO2-hydrate-bearing sediments. Clearly, the Yonaguni Knoll is an exceptional natural laboratory for the study of consequences of CO2 disposal as well as of natural CO2 reservoirs as potential microbial habitats on early Earth and other celestial bodies.
KW - Anaerobic oxidation of methane
KW - CO disposal
KW - CO hydrate
KW - Chemolithotroph
KW - Liquid CO
UR - http://www.scopus.com/inward/record.url?scp=33748989249&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33748989249&partnerID=8YFLogxK
U2 - 10.1073/pnas.0606083103
DO - 10.1073/pnas.0606083103
M3 - Article
C2 - 16959888
AN - SCOPUS:33748989249
VL - 103
SP - 14164
EP - 14169
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 38
ER -