Article

Inter-field variability in the microbial communities of hydrothermal vent deposits from a back-arc basin

Department of Biology, Portland State University, Portland, OR, USA.
Geobiology (Impact Factor: 3.69). 03/2012; 10(4):333-46. DOI: 10.1111/j.1472-4669.2012.00325.x
Source: PubMed

ABSTRACT Diverse microbial communities thrive on and in deep-sea hydrothermal vent mineral deposits. However, our understanding of the inter-field variability in these communities is poor, as limited sampling and sequencing efforts have hampered most previous studies. To explore the inter-field variability in these communities, we used barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA gene to characterize the archaeal and bacterial communities of over 30 hydrothermal deposit samples from six vent fields located along the Eastern Lau Spreading Center. Overall, the bacterial and archaeal communities of the Eastern Lau Spreading Center are similar to other active vent deposits, with a high diversity of Epsilonproteobacteria and thermophilic Archaea. However, the archaeal and bacterial communities from the southernmost vent field, Mariner, were significantly different from the other vent fields. At Mariner, the epsilonproteobacterial genus Nautilia and the archaeal family Thermococcaceae were prevalent in most samples, while Lebetimonas and Thermofilaceae were more abundant at the other vent fields. These differences appear to be influenced in part by the unique geochemistry of the Mariner fluids resulting from active degassing of a subsurface magma chamber. These results show that microbial communities associated with hydrothermal vent deposits in back-arc basins are taxonomically similar to those from mid-ocean ridge systems, but differences in geologic processes between vent fields in a back-arc basin can influence microbial community structure.

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    • "We expanded on existing microbiological observations from similar geologic settings (e.g. Kato et al., 2010; Flores et al., 2012; Sylvan et al., 2013) to illustrate the dominance of the rTCA pathway in vent primary productivity on active structures that emit H 2S-rich and H2 and CH4-poor fluids. Our data also further offer new detail through a more refined subsampling strategy, suggesting hitherto unobserved variations in δ "
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    • "Our study on the distribution of the Aquificales along the ELSC/VFR shows that the communities differ between distinct geographical locations and are influenced by the host-rock of the vent field and deposit type where they were detected. These trends are similar to those reported by other authors [4] [11] [37] who showed a north–south shift in microbial diversity patterns in different vent communities concomitant with the north–south geochemical gradient along the ELSC/VFR. Furthermore, our comprehensive survey revealed that the ELSC/VFR contains the largest diversity of Aquificales ever reported in a single geographical area and that this geochemical diverse system may harbor new members of the Aquificales, in particular, some Hydrogenothermaceae that might be 'endemic' to this hydrothermal system. "
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