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| Boulart, Cedric; Chavagnac, Valerie; Monnin, Christophe; Delacour, Adelie; Ceuleneer, Georges; Hoareau, Guilhem. |
| Serpentinisation of mantle rocks, leading to natural venting of hydrogen and methane, has been reported to occur at the global scale, wherever fluids percolate in ultramafic formations. Here we compare gas composition from two on-land, low-temperature, and hyper-alkaline springs hosted on ultramafic rocks in the ophiolite massifs of the Sultanate of Oman and the Ligurian Alps (Voltri Group, Genoa region, Northern Italy). These two settings exhibit similar chemical and mineralogical features but show diverse styles of gas venting. Commonly to all hyper-alkaline springs, gases are characterised by relatively high N-2, very low O-2 and CO2 concentrations, and a strong enrichment in H-2 and CH4. The comparison between Oman and Liguria highlights a high... |
| Tipo: Text |
Palavras-chave: Methane; Hydrogen; Gas composition; Hyper-alkaline springs. Oman; Voltri Massif. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00175/28634/27059.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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