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Sauter, Daniel; Cannat, Mathilde; Roumejon, Stephane; Andreani, Muriel; Birot, Dominique; Bronner, Adrien; Brunelli, Daniele; Carlut, Julie; Delacour, Adelie; Guyader, Vivien; Macleod, Christopher J.; Manatschal, Gianreto; Mendel, Veronique; Menez, Benedicte; Pasini, Valerio; Ruellan, Etienne; Searle, Roger. |
The global mid-ocean ridge system, where tectonic plates diverge, is traditionally thought of as the largest single volcanic feature on the Earth. Yet, wide expanses of smooth sea floor in the easternmost part of the Southwest Indian Ridge in the Indian Ocean lacks the hummocky morphology that is typical for submarine volcanism. At other slow-spreading ridges, the sea floor can extend by faulting the existing lithosphere, along only one side of the ridge axis. However, the smooth sea floor in the easternmost Southwest Indian Ridge also lacks the corrugated texture created by such faulting. Instead, the sea floor is smooth on both sides of the ridge axis and is thought to be composed of altered mantle-derived rocks. Here we use side-scan sonar to image the... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00136/24771/22950.pdf |
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Mei, Nan; Postec, Anne; Monnin, Christophe; Pelletier, Bernard; Payri, Claude E.; Menez, Benedicte; Frouin, Eleonore; Ollivier, Bernard; Erauso, Gael; Quemeneur, Marianne. |
High amounts of hydrogen are emitted in the serpentinite-hosted hydrothermal field of the Prony Bay (PHF, New Caledonia), where high-pH (similar to 11), low-temperature (< 40 degrees C), and low-salinity fluids are discharged in both intertidal and shallow submarine environments. In this study, we investigated the diversity and distribution of potentially hydrogen-producing bacteria in Prony hyperalkaline springs by using metagenomic analyses and different PCR-amplified DNA sequencing methods. The retrieved sequences of hydA genes, encoding the catalytic subunit of [FeFe]-hydrogenases and, used as a molecular marker of hydrogen-producing bacteria, were mainly related to those of Firmicutes and clustered into two distinct groups depending on sampling... |
Tipo: Text |
Palavras-chave: Hydrogen; Microbial diversity; Hydrogen producers; Serpentinization; HydA genes; [FeFe]-hydrogenase; Metagenomics. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00467/57913/60308.pdf |
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Postec, Anne; Quemeneur, Marianne; Bes, Meline; Mei, Nan; Benaissa, Fatma; Payri, Claude; Pelletier, Bernard; Monnin, Christophe; Guentas-dombrowsky, Linda; Ollivier, Bernard; Gerard, Emmanuelle; Pisapia, Celine; Gerard, Martine; Menez, Benedicte; Erauso, Gael. |
Active carbonate chimneys from the shallow marine serpentinizing Prony Hydrothermal Field were sampled 3 times over a 6 years period at site ST09. Archaeal and bacterial communities composition was investigated using PCR-based methods (clone libraries, Denaturating Gel Gradient Electrophoresis, quantitative PCR) targeting 16S rRNA genes, methyl coenzyme M reductase A and dissimilatory sulfite reductase subunit B genes. Methanosarcinales (Euryarchaeota) and Thaumarchaea were the main archaeal members. The Methanosarcinales, also observed by epifluorescent microscopy and FISH, consisted of two phylotypes that were previously solely detected in two other serpentinitzing ecosystems (The Cedars and Lost City Hydrothermal Field). Surprisingly, members of the... |
Tipo: Text |
Palavras-chave: Hydrothermal; Serpentinization; Alkaline; Prony; Microbial communities. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00467/57916/60307.pdf |
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Pisapia, Celine; Gerard, Emmanuelle; Gerard, Martine; Lecourt, Lena; Lang, Susan Q.; Pelletier, Bernard; Payri, Claude E.; Monnin, Christophe; Guentas, Linda; Postec, Anne; Quemeneur, Marianne; Erauso, Gael; Menez, Benedicte. |
Despite their potential importance as analogs of primitive microbial metabolisms, the knowledge of the structure and functioning of the deep ecosystems associated with serpentinizing environments is hampered by the lack of accessibility to relevant systems. These hyperalkaline environments are depleted in dissolved inorganic carbon (DIC), making the carbon sources and assimilation pathways in the associated ecosystems highly enigmatic. The Prony Bay Hydrothermal Field (PHF) is an active serpentinization site where, similar to Lost City (Mid-Atlantic Ridge), high-pH fluids rich in H-2 and CH4 are discharged from carbonate chimneys at the seafloor, but in a shallower lagoonal environment. This study aimed to characterize the subsurface microbial ecology of... |
Tipo: Text |
Palavras-chave: Serpentinization; Alkaline hydrothermalism; Deep life; Firmicutes; Acetothermia; Omnitrophica; Organic carbon. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00467/57909/60314.pdf |
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Henri, Pauline A.; Rommevaux-jestin, Celine; Lesongeur, Francoise; Mumford, Adam; Emerson, David; Godfroy, Anne; Menez, Benedicte. |
To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W). In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped... |
Tipo: Text |
Palavras-chave: Basaltic glass; Zetaproteobacteria; Bio-mediated alteration; Iron-oxidation; Abyssal plain. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00378/48894/49332.pdf |
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