Le Moine Bauer Sven, Lu Guang-Sin, Goulaouic Steven, Puzenat Valentine, Schouw Anders, Barreyre Thibaut, Pawlowsky-Glahn Vera, Egozcue Juan José, Martelat Jean-Emmanuel, Escartin Javier, Amend Jan P, Nomikou Paraskevi, Vlasopoulos Othonas, Polymenakou Paraskevi, Jørgensen Steffen Leth
Center for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, Norway.
Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, Seattle, WA, United States.
Front Microbiol. 2023 Jan 6;13:1060168. doi: 10.3389/fmicb.2022.1060168. eCollection 2022.
Shallow hydrothermal systems share many characteristics with their deep-sea counterparts, but their accessibility facilitates their study. One of the most studied shallow hydrothermal vent fields lies at Paleochori Bay off the coast of Milos in the Aegean Sea (Greece). It has been studied through extensive mapping and its physical and chemical processes have been characterized over the past decades. However, a thorough description of the microbial communities inhabiting the bay is still missing.
We present the first in-depth characterization of the prokaryotic communities of Paleochori Bay by sampling eight different seafloor types that are distributed along the entire gradient of hydrothermal influence. We used deep sequencing of the 16S rRNA marker gene and complemented the analysis with qPCR quantification of the 16S rRNA gene and several functional genes to gain insights into the metabolic potential of the communities.
We found that the microbiome of the bay is strongly influenced by the hydrothermal venting, with a succession of various groups dominating the sediments from the coldest to the warmest zones. Prokaryotic diversity and abundance decrease with increasing temperature, and thermophilic archaea overtake the community.
Relevant geochemical cycles of the Bay are discussed. This study expands our limited understanding of subsurface microbial communities in acidic shallow-sea hydrothermal systems and the contribution of their microbial activity to biogeochemical cycling.
浅海热液系统与其深海对应物具有许多共同特征，但因其易于接近，便于开展研究。其中一个研究最多的浅海热液喷口区位于爱琴海（希腊）米洛斯岛海岸外的帕莱奥乔里湾。在过去几十年里，人们通过广泛测绘对其进行了研究，并对其物理和化学过程进行了表征。然而，对栖息在该海湾的微生物群落仍缺乏全面描述。
我们通过对沿热液影响的整个梯度分布的八种不同海底类型进行采样，首次对帕莱奥乔里湾的原核生物群落进行了深入表征。我们使用16S rRNA标记基因进行深度测序，并通过对16S rRNA基因和几个功能基因进行qPCR定量分析来补充分析，以深入了解群落的代谢潜力。
我们发现，该海湾的微生物组受到热液排放的强烈影响，从最冷到最暖的区域，沉积物中依次有不同的菌群占主导地位。原核生物的多样性和丰度随温度升高而降低，嗜热古菌占据了群落主导地位。
讨论了该海湾相关的地球化学循环。本研究扩展了我们对酸性浅海热液系统中地下微生物群落及其微生物活动对生物地球化学循环贡献的有限认识。
