Ehrhardt Christopher J, Haymon Rachel M, Lamontagne Michael G, Holden Patricia A
Department of Earth Sciences, UC-Santa Barbara, Santa Barbara, CA 93106, USA.
Environ Microbiol. 2007 Apr;9(4):900-12. doi: 10.1111/j.1462-2920.2006.01211.x.
Little is known about the fluids or the microbial communities present within potentially vast hydrothermal reservoirs contained in still-hot volcanic ocean crust beneath the flanks of the mid-ocean ridge. During Alvin dives in 2002, organic material attached to basalt was collected at low, near-ambient temperatures from an abyssal hill fault scarp in 0.5 Ma lithosphere on the western ridge flank of the East Pacific Rise. Mineral analysis by X-ray diffractometry and scanning electron microscopy revealed high-temperature (> 110 degrees C) phases chalcopyrite (Cu(5)FeS(4)) and 1C pyrrhotite (Fe(1-x)S) within the fault scarp materials. A molecular survey of archaeal genes encoding 16S rRNA identified a diverse hyperthermophilic community, including groups within Crenarchaeota, Euryarchaeota, and Korarchaeota. We propose that the sulfide, metals and archaeal communities originated within a basalt-hosted subseafloor hydrothermal habitat beneath the East Pacific Rise ridge flank and were transported to the seafloor during a recent episode of hydrothermal venting from the abyssal hill fault. Additionally, inferred metabolisms from the fault scarp community suggest that an ecologically unique high-temperature archaeal biosphere may thrive beneath the young East Pacific Rise ridge flank and that abyssal hill fault scarps may present new opportunities for sampling for this largely unexplored microbial habitat.
对于存在于大洋中脊侧翼下方仍处于高温状态的火山洋壳中潜在的巨大热液储层内的流体和微生物群落，我们了解甚少。在2002年“阿尔文”号潜水考察期间，在东太平洋海隆西翼0.5 Ma岩石圈的一座深海丘陵断层崖处，于接近环境温度的低温条件下收集了附着在玄武岩上的有机物质。通过X射线衍射和扫描电子显微镜进行的矿物分析揭示，断层崖物质中存在高温（>110摄氏度）相的黄铜矿（Cu(5)FeS(4)）和1C磁黄铁矿（Fe(1 - x)S）。一项对编码16S rRNA的古菌基因的分子调查识别出了一个多样的嗜热群落，包括泉古菌门、广古菌门和初古菌门中的类群。我们提出，硫化物、金属和古菌群落起源于东太平洋海隆侧翼下方玄武岩为主的海底热液生境，并在最近一次从深海丘陵断层发生热液喷发期间被输送到了海底。此外，从断层崖群落推断出的代谢情况表明，一个生态上独特的高温古菌生物圈可能在年轻的东太平洋海隆侧翼下方繁盛，并且深海丘陵断层崖可能为采样这个大部分未被探索的微生物生境提供新的机会。
