Microbial Communities on Seafloor Basalts at Dorado Outcrop Reflect Level of Alteration and Highlight Global Lithic Clades.
Microbial Communities on Seafloor Basalts at Dorado Outcrop Reflect Level of Alteration and Highlight Global Lithic Clades.
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DOI：
10.3389/fmicb.2015.01470
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发表时间：
2015
影响因子：
5.2
通讯作者：
Orcutt BN
中科院分区：
文献类型：
--
作者：
Lee MD;Walworth NG;Sylvan JB;Edwards KJ;Orcutt BN
沿着洋中脊和海底露头的玄武岩裸露区是流体流入和流出地下海洋的通道，微生物-矿物相互作用可影响岩石-水界面的蚀变反应。多拉多露头位于东太平洋海隆东侧，是一个低温（<20°C）热液喷口，是目前海底玄武岩生物群落调查中的一个新端元。与先前的研究一致，使用针对V4高变区的通用引物对16 S rRNA基因序列多样性进行的调查显示，海底岩石的丰富性和多样性远远高于周围海水。总的来说，γ-，α-和δ-变形菌，和Thaumarchaeota占主导地位的测序社区，共同构成了超过一半的观察到的多样性，虽然细菌序列比古细菌在所有样本中更丰富。最丰富的细菌读数密切相关的专性chemolithoautotrophic的，硫氧化的Thioprofundum lithotrophicum，这表明碳和硫循环在这个系统中占主导地位的代谢途径。与底层水相比，在玄武岩上检测到相对较高丰度的Thaumarchaeota代表，可能表明氨氧化。与全球分布的海底玄武岩的其他序列数据集相比，这项研究揭示了许多重叠和世界性的系统发育组，也表明，基板年龄与群落结构。
Areas of exposed basalt along mid-ocean ridges and at seafloor outcrops serve as conduits of fluid flux into and out of a subsurface ocean, and microbe–mineral interactions can influence alteration reactions at the rock–water interface. Located on the eastern flank of the East Pacific Rise, Dorado Outcrop is a site of low-temperature (<20°C) hydrothermal venting and represents a new end-member in the current survey of seafloor basalt biomes. Consistent with prior studies, a survey of 16S rRNA gene sequence diversity using universal primers targeting the V4 hypervariable region revealed much greater richness and diversity on the seafloor rocks than in surrounding seawater. Overall, Gamma-, Alpha-, and Deltaproteobacteria, and Thaumarchaeota dominated the sequenced communities, together making up over half of the observed diversity, though bacterial sequences were more abundant than archaeal in all samples. The most abundant bacterial reads were closely related to the obligate chemolithoautotrophic, sulfur-oxidizing Thioprofundum lithotrophicum, suggesting carbon and sulfur cycling as dominant metabolic pathways in this system. Representatives of Thaumarchaeota were detected in relatively high abundance on the basalts in comparison to bottom water, possibly indicating ammonia oxidation. In comparison to other sequence datasets from globally distributed seafloor basalts, this study reveals many overlapping and cosmopolitan phylogenetic groups and also suggests that substrate age correlates with community structure.