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Kato S, Kobayashi C, Kakegawa T, Yamagishi A.. Microbial communities in iron-silica-rich microbial mats at deep-sea hydrothermal fields of the southern Mariana Trough. Environ Microbiol 11: 2094-2111

Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan.
Environmental Microbiology (Impact Factor: 6.2). 05/2009; 11(8):2094-111. DOI: 10.1111/j.1462-2920.2009.01930.x
Source: PubMed

ABSTRACT

The abundance, diversity and composition of bacterial and archaeal communities in the microbial mats at deep-sea hydrothermal fields were investigated, using culture-independent 16S rRNA and functional gene analyses combined with mineralogical analysis. Microbial mats were collected at two hydrothermal areas on the ridge of the back-arc spreading centre in the Southern Mariana Trough. Scanning electron microscope and energy dispersive X-ray spectroscopic (SEM-EDS) analyses revealed that the mats were mainly composed of amorphous silica and contained numerous filamentous structures of iron hydroxides. Direct cell counting with SYBR Green I staining showed that the prokaryotic cell densities were more than 10(8) cells g(-1). Quantitative polymerase chain reaction (Q-PCR) analysis revealed that Bacteria are more abundant than Archaea in the microbial communities. Furthermore, zetaproteobacterial cells accounted for 6% and 22% of the prokaryotic cells in each mat estimated by Q-PCR with newly designed primers and TaqMan probe. Phylotypes related to iron-oxidizers, methanotrophs/methylotrophs, ammonia-oxidizers and sulfate-reducers were found in the 16S rRNA gene clone libraries constructed from each mat sample. A variety of unique archaeal 16S rRNA gene phylotypes, several pmoA, dsrAB and archaeal amoA gene phylotypes were also recovered from the microbial mats. Our results provide insights into the diversity and abundance of microbial communities within microbial mats in deep-sea hydrothermal fields.

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    • "In contrast, 78.3% of the number of total OTUs detected in the subsamples was not shared with those detected in the inactive chimneys. We performed principal coordinate analysis (PCoA) to compare microbial community compositions between the sub-seafloor sulfide samples and several seafloor samples, i.e., active and inactive chimneys (Suzuki et al., 2004; Kato et al., 2010; Sylvan et al., 2012; 2013), ironrich mats (Kato et al., 2009a), a manganese crust (Nitahara et al., 2011) and basaltic rocks (Santelli et al., 2008; Sylvan et al., 2013). The PCoA showed that the communities of the sub-seafloor sulfide samples were not closely related to those of the other samples (Fig. 3), which was consistent with the presence of many unique OTUs. "

    Full-text · Dataset · Aug 2015
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    • "In contrast, 78.3% of the number of total OTUs detected in the subsamples was not shared with those detected in the inactive chimneys. We performed principal coordinate analysis (PCoA) to compare microbial community compositions between the sub-seafloor sulfide samples and several seafloor samples, i.e., active and inactive chimneys (Suzuki et al., 2004; Kato et al., 2010; Sylvan et al., 2012; 2013), ironrich mats (Kato et al., 2009a), a manganese crust (Nitahara et al., 2011) and basaltic rocks (Santelli et al., 2008; Sylvan et al., 2013). The PCoA showed that the communities of the sub-seafloor sulfide samples were not closely related to those of the other samples (Fig. 3), which was consistent with the presence of many unique OTUs. "

    Full-text · Dataset · Aug 2015
    • "MBGE sequences were more abundant in the clone libraries of the upper convective layers of Atlantis II Deep than in other samples. This is consistent with previous reports indicating that they frequently occur at locations with higher temperatures (50 Ce63 C), correlating with the high G þ C content of their 16S rRNA gene sequences[44]. They were often retrieved from deep-sea sediment, hydrothermal environments , chimney samples[45]and iron-rich habitats[46]. "
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    ABSTRACT: Oceanic deep hypersaline anoxic basins (DHABs) are characterized by drastic changes in physico-chemical conditions in the transition from overlaying seawater to brine body. Brine-seawater interfaces (BSIs) of several DHABs across the Mediterranean Sea have been shown to possess methanogenic and sulfate-reducing activities, yet no systematic studies have been conducted to address the potential functional diversity of methanogenic and sulfate-reducing communities in the Red Sea DHABs. Here, we evaluated the relative abundance of Bacteria and Archaea using quantitative PCR and conducted phylogenetic analyses of nearly full-length 16S rRNA genes as well as functional marker genes encoding the alpha subunits of methyl-coenzyme M reductase (mcrA) and dissimilatory sulfite reductase (dsrA). Bacteria predominated over Archaea in most locations, the majority of which were affiliated with Deltaproteobacteria, while Thaumarchaeota were the most prevalent Archaea in all sampled locations. The upper convective layers of Atlantis II Deep, which bear increasingly harsh environmental conditions, were dominated by members of the class Thermoplasmata (Marine Benthic Group E and Mediterranean Sea Brine Lakes Group 1). Our study revealed unique microbial compositions, the presence of niche-specific groups, and collectively, a higher diversity of sulfate-reducing communities compared to methanogenic communities in all five studied locations. Copyright © 2015. Published by Elsevier Masson SAS.
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