Microbial community in a sediment-hosted CO2 lake of the southern Okinawa Trough hydrothermal system
Microbial community in a sediment-hosted CO2 lake of the southern Okinawa Trough hydrothermal system
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DOI：
10.1073/pnas.0606083103
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发表时间：
2006-09-19
影响因子：
11.1
通讯作者：
Boetius, Antje
中科院分区：
文献类型：
--
作者：
Inagaki, Fumio;Kuypers, Marcel M. M.;Boetius, Antje
大气中二氧化碳含量的增加预计将导致气候变化，对地球生态系统和人类社会产生负面影响。因此，讨论了多种二氧化碳处理方案，包括将其注入深海。由于CO2在海水中的溶解将大大降低环境pH值，因此预计会对深水生态系统产生负面影响。因此，与深海天然Co-2储存库相关的生态系统，以及这些环境中气态、液态和固态CO2的动态变化，是科学界和社会的极大兴趣。本文报道了冲绳海槽南部Yonaguni Knoll IV热液区深海沉积物上的微生物群落的生物地球化学和微生物学特征。我们在CO2湖上方的沉积物路面中发现了高丰度（bbb10 (9) CM-3）的微生物细胞，而在液态CO2/CO2-水合物界面处，微生物细胞数量下降到惊人的低（107 CM-3）。沉积物中的关键类群为：(1)Deltaproteobacteria中的厌氧甲烷营养古细菌ANME-2c和Eel-2类群；(2)Gamma- proteobacteria和Epsilonproteobacteria中的硫代谢化养生物。与单碳同化相关的功能基因检测以及高度c -13缺失的古细菌和细菌脂质生物标志物的存在表明，吸收CO2和/或CH4的微生物在液态CO2和含CO2水合物的沉积物中占主导地位。显然，与那国丘是一个特殊的天然实验室，用于研究二氧化碳处置的后果，以及作为早期地球和其他天体上潜在微生物栖息地的天然二氧化碳储存库。
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 Co-2 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 (> 10(9) 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/CO2-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 C-13-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.