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| Registros recuperados: 42 | |
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| Takai, Ken; Miyazaki, Masayuki; Hirayama, Hisako; Nakagawa, Satoshi; Querellou, Joel; Godfroy, Anne. |
| P>Two novel, thermophilic piezophiles, capable of chemolithoautotrophic growth, are successfully cultivated and isolated from a black smoker chimney at the TAG field (Mid Atlantic Ridge: MAR) by using a piezophilic cultivation technique. Both strains (strains 106 and 108) represent dominant cultivated populations of the microbial communities in the chimney surface habitat. Strain 106 represents typically thin, long spiral cells under the piezophilic growth condition but short bent cells under the non-piezophilic condition. It is a strictly chemolithoautotrophic gammaproteobacterium using reduced sulfur compounds as the electron donors, and nitrate and O-2 as the electron acceptors. Based on the 16S rRNA gene sequence, strain 106 would represent a novel... |
| Tipo: Text |
Palavras-chave: Sp. nov.; Ecological signifiance; Hydrostatic pressure; Subsurface biosphere; Base composition; High temperature; Membrane lipids; Gen. nov.; Microorganisms; Diversity. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6652.pdf |
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| Ciobanu, Maria Cristina; Burgaud, Gaetan; Dufresne, Alexis; Breuker, Anja; Redou, Vanessa; Ben Maamar, Sarah; Gaboyer, Frederic; Vandenabeele-trambouze, Odile; Lipp, Julius Sebastian; Schippers, Axel; Vandenkoornhuyse, Philippe; Barbier, Georges; Jebbar, Mohamed; Godfroy, Anne; Alain, Karine. |
| The subsurface realm is colonized by microbial communities to depths of >1000 meters below the seafloor (m.b.sf.), but little is known about overall diversity and microbial distribution patterns at the most profound depths. Here we show that not only Bacteria and Archaea but also Eukarya occur at record depths in the subseafloor of the Canterbury Basin. Shifts in microbial community composition along a core of nearly 2 km reflect vertical taxa zonation influenced by sediment depth. Representatives of some microbial taxa were also cultivated using methods mimicking in situ conditions. These results suggest that diverse microorganisms persist down to 1922 m.b.sf. in the seafloor of the Canterbury Basin and extend the previously known depth limits of... |
| Tipo: Text |
Palavras-chave: Deep biosphere; Subsurface life; Eukaryote; Record depth. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31243/29895.pdf |
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| Cruaud, Perrine; Vigneron, Adrien; Lucchetti-miganeh, Celine; Ciron, Pierre Emmanuel; Godfroy, Anne; Cambon-bonavita, Marie-anne. |
| Next-generation sequencing (NGS) opens up exciting possibilities for improving our knowledge of environmental microbial diversity, allowing rapid and cost-effective identification of both cultivated and uncultivated microorganisms. However, library preparation, sequencing, and analysis of the results can provide inaccurate representations of the studied community compositions. Therefore, all these steps need to be taken into account carefully. Here we evaluated the effects of DNA extraction methods, targeted 16S rRNA hypervariable regions, and sample origins on the diverse microbes detected by 454 pyrosequencing in marine cold seep and hydrothermal vent sediments. To assign the reads with enough taxonomic precision, we built a database with about 2,500... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00204/31495/29907.pdf |
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| Landreau, M.; Duthoit, Frederique; Roussel, Erwan; Schonherr, S.; Georges, Myriam; Godfroy, Anne; Le Blay, G.. |
| Cultivation in a bioreactor of immobilized deep-sea hydrothermal microbial community was tested in order to assess the stability and reactivity of this new system. A community composed of 8 hydrothermal strains was entrapped in a polymer matrix that was used to inoculate a continuous culture in a gas-lift bioreactor. The continuous culture was performed for 41 days at successively 60°C, 55°C, 60°C, 85°C and 60°C, at pH 6.5, in anaerobic condition and constant dilution rate. Oxic stress and pH variations were tested at the beginning of the incubation. Despite these detrimental conditions, 3 strains including 2 strict anaerobes were maintained in the bioreactor. High cell concentrations (3 × 108 cells mL−1) and high ATP contents were measured in both liquid... |
| Tipo: Text |
Palavras-chave: Immobilization; Anaerobiosis; Marine (hyper)thermophiles; Continuous culture. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45851/45516.pdf |
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| Portail, Marie; Olu, Karine; Escobar-briones, E.; Caprais, Jean-claude; Menot, Lenaick; Waeles, Mathieu; Cruaud, Perrine; Sarradin, Pierre-marie; Godfroy, Anne; Sarrazin, Jozee. |
| Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00280/39076/37642.pdf |
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| Wery, Nathalie; Lesongeur, Francoise; Pignet, Patricia; Derennes, Veronique; Cambon-bonavita, Marie-anne; Godfroy, Anne; Barbier, Georges. |
| A thermophilic, anaerobic, chemo-organotrophic sulfur-reducing bacterium, designated MV1075(T), was isolated from a deep-sea hydrothermal chimney sample collected on the Mid-Atlantic Ridge. Cells were rod-shaped with a sheath-like outer structure, motile with polar flagella and stained Gramnegative. They appeared singly, in pairs or in short chains. The temperature range for growth was 25-65 degreesC, with an optimum at 55 degreesC. Growth was observed from ph 5 to ph 9, and the optimum ph was around 7. The salinity range for growth was 15-70 g sea salt I-1 (corresponding to 10-45 g NaCl I-1), with an optimum at 30 g I-1 (20 g NaCl I-1). The isolate was able to grow on a broad spectrum of carbohydrates or complex proteinaceous substrates. Sulfur was not... |
| Tipo: Text |
Palavras-chave: Marinitoga camini; Thermotogales; Thermophile; Deep sea hydrothermal vent. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-587.pdf |
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| Postec, Anne; Pignet, Patricia; Cueff-gauchard, Valerie; Schmitt, Anne; Querellou, Joel; Godfroy, Anne. |
| The hyperthermophilic archaeon Thermococcus hydrothermalis was cultivated in continuous culture in a gas-lift bioreactor in the absence of elemental sulphur on both proteinaceous and maltose-containing media. Optimal conditions (pH, temperature and gas flow rate), determined on complex media that yielded maximal growth rate and maximal steady state cell density, were obtained at 80degreesC, pH 6 and gas sparging at 0.2 v v(-1) min(-1). Higher steady state cell densities were obtained on a medium containing maltose and yeast extract. In order to design a defined and minimal media, the nutritional requirements of T hydrothermalis were then investigated using continuous culture in the absence of elemental sulphur in the gas-lift bioreactor. First, the complex... |
| Tipo: Text |
Palavras-chave: Bioreactor; Defined and minimal media; Culture optimisation; Gas lift bioreactor; Thermococcus hydrothermalis. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-365.pdf |
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| Vigneron, Adrien; L Haridon, Stephane; Godfroy, Anne; Roussel, Erwan; Cragg, Barry A.; Parkes, R. John; Toffin, Laurent. |
| In the Sonora Margin cold seep ecosystems (Gulf of California), sediments underlying microbial mats harbor high biogenic methane concentrations, fueling various microbial communities, such as abundant lineages of anaerobic methanotrophs (ANME). However, the biodiversity, distribution, and metabolism of the microorganisms producing this methane remain poorly understood. In this study, measurements of methanogenesis using radiolabeled dimethylamine, bicarbonate, and acetate showed that biogenic methane production in these sediments was mainly dominated by methylotrophic methanogenesis, while the proportion of autotrophic methanogenesis increased with depth. Congruently, methane production and methanogenic Archaea were detected in culture enrichments amended... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00256/36737/35338.pdf |
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| Cruaud, Perrine; Vigneron, Adrien; Pignet, Patricia; Caprais, Jean-claude; Lesongeur, Francoise; Toffin, Laurent; Godfroy, Anne; Cambon-bonavita, Marie-anne. |
| In the Guaymas Basin, the presence at a few tens of kilometers of cold seeps and hydrothermal vents coupled with comparable sedimentary settings and depths offer a unique opportunity to assess and compare the microbial community composition of these deep-sea ecosystems. The microbial diversity in sediments from three cold seep and two hydrothermal vent assemblages were investigated using high-throughput 16S rRNA-sequencing. Numerous bacterial and archaeal lineages were detected in both cold seep and hydrothermal vent sediments. Various potential organic matter degraders (e.g., Chloroflexi, Atribacteria, MBG-D) and methane and sulfur cycling related microorganisms (e.g., ANME and methanogenic lineages, sulfate-reducing lineages) were detected in both... |
| Tipo: Text |
Palavras-chave: Microbial diversity; Hydrothermal vents; Cold seeps; Ribotypes; Methane; Extreme environments. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00415/52640/53496.pdf |
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| Cruaud, Perrine; Vigneron, Adrien; Pignet, Patricia; Caprais, Jean-claude; Lesongeur, Francoise; Toffin, Laurent; Godfroy, Anne; Cambon-bonavita, Marie-anne. |
| The Sonora Margin cold seeps present a seafloor mosaic pattern consisting of different faunal assemblages and microbial mats. To better understand if sedimentary microbial communities reflect this patchy distribution, all major habitats were investigated using four complementary approaches: 16S rRNA gene sequence 454 pyrosequencing, quantitative polymerase chain reaction, fluorescence in situ hybridization and geochemistry analyses. This study reveals that sediments populated by different surface assemblages show distinct porewater geochemistry features and are associated with distinct microbial communities. In the sediments underlying the microbial mat and the surrounding macrofauna, microbial communities were dominated by anaerobic methane oxidizers... |
| Tipo: Text |
Palavras-chave: Microbial communities; Pyrosequencing; MBG-D; ANME; Faunal assemblages; Vesicomyidae; Siboglinidae; Microbial mat. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00288/39889/38434.pdf |
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| Mercier, Coraline; Lossouarn, Julien; Haverkamp, Thomas; Bienvenu, Nadège; Godfroy, Anne; Cueff-gauchard, Valerie; Geslin, Claire; Nesbo, Camilla. |
| Here, we present the draft genome sequences of two thermophilic Marinitoga strain members of the Thermotogales order, Marinitoga camini DV1155 and Marinitoga camini DV1197. These strains were isolated from deep-sea hydrothermal vents of the Mid-Atlantic Ridge. |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00357/46833/46708.pdf |
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| Byrne, Nathalie; Lesongeur, Francoise; Bienvenu, Nadege; Geslin, Claire; Alain, Karine; Prieur, Daniel; Godfroy, Anne. |
| Both cultivation and molecular techniques were used to investigate the microbial diversity and dynamic of a deep-sea vent chimney. The enrichment cultures performed in a gas-lift bioreactor were inoculated with a black smoker chimney sample collected on TAG site on the mid-Atlantic ridge. To mimic as close as possible environmental conditions, the cultures were performed in oligotrophic medium with nitrogen, hydrogen and carbon dioxide (N-2/H-2/CO2) gas sweeping. Also, the temperature was first settled at a temperature of 85A degrees C and colloidal sulphur was added. Then, the temperature was lowered to 60A degrees C and sulphur was omitted. Archaeal and bacterial diversity was studied in both culture and natural samples. Through 16S rRNA gene sequences... |
| Tipo: Text |
Palavras-chave: 16S rRNA genes; Oligotrophic condition; Environmental condition; Bioreactor; Continuous enrichment culture; Microbial diversity; Deep sea hydrothermal vent. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6920.pdf |
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| Pluchon, Pierre Francois; Fouqueau, Thomas; Creze, Christophe; Laurent, Sebastien; Briffotaux, Julien; Hogrel, Gaelle; Palud, Adeline; Henneke, Ghislaine; Godfroy, Anne; Hausner, Winfried; Thomm, Michael; Nicolas, Jacques; Flament, Didier. |
| In Archaea, the proteins involved in the genetic information processing pathways, including DNA replication, transcription, and translation, share strong similarities with those of eukaryotes. Characterizations of components of the eukaryotic-type replication machinery complex provided many interesting insights into DNA replication in both domains. In contrast, DNA repair processes of hyperthermophilic archaea are less well understood and very little is known about the intertwining between DNA synthesis, repair and recombination pathways. The development of genetic system in hyperthermophilic archaea is still at a modest stage hampering the use of complementary approaches of reverse genetics and biochemistry to elucidate the function of new candidate DNA... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00171/28198/26556.pdf |
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| Appolaire, Alexandre; Rosenbaum, Eva; Dura, M. Asuncion; Colombo, Matteo; Marty, Vincent; Savoye, Marjolaine Noirclerc; Godfroy, Anne; Schoehn, Guy; Girard, Eric; Gabel, Frank; Franzetti, Bruno. |
| Tetrahedral (TET) aminopeptidases are large polypeptide destruction machines present in prokaryotes and eukaryotes. Here, the rules governing their assembly into hollow 12-subunit tetrahedrons are addressed by using TET2 from Pyrococcus horikoshii (PhTET2) as a model. Point mutations allowed the capture of a stable, catalytically active precursor. Small angle x- ray scattering revealed that it is a dimer whose architecture in solution is identical to that determined by x- ray crystallography within the fully assembled TET particle. Small angle x- ray scattering also showed that the reconstituted PhTET2 dodecameric particle displayed the same quaternary structure and thermal stability as the wild-type complex. The PhTET2 assembly intermediates were... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00177/28820/27491.pdf |
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| Vigneron, Adrien; Cruaud, Perrine; Pignet, Patricia; Caprais, Jean-claude; Gayet, Nicolas; Cambon-bonavita, Marie-anne; Godfroy, Anne; Toffin, Laurent. |
| The Sonora Margin cold seeps present on the seafloor a patchiness pattern of white microbial mats surrounded by polychaete and gastropod beds. These surface assemblages are fuelled by abundant organic inputs sedimenting from the water column and upward-flowing seep fluids. Elevated microbial density was observed in the underlying sediments. A previous study on the same samples identified anaerobic oxidation of methane (AOM) as the potential dominant archaeal process in these Sonora Margin sediments, probably catalysed by three clades of archaeal anaerobic methanotrophs (ANME-1, ANME-2 and ANME-3) associated with bacterial syntrophs. In this study, molecular surveys and microscopic observations investigating the diversity of Bacteria involved in AOM... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00168/27921/27279.pdf |
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| Postec, Anne; Lesongeur, Francoise; Pignet, Patricia; Ollivier, B; Querellou, Joel; Godfroy, Anne. |
| The prokaryotic diversity of culturable thermophilic communities of deep-sea hydrothermal chimneys was analysed using a continuous enrichment culture performed in a gas-lift bioreactor, and compared to classical batch enrichment cultures in vials. Cultures were conducted at 60 degrees C and pH 6.5 using a complex medium containing carbohydrates, peptides and sulphur, and inoculated with a sample of a hydrothermal black chimney collected at the Rainbow field, Mid-Atlantic Ridge, at 2,275 m depth. To assess the relevance of both culture methods, bacterial and archaeal diversity was studied using cloning and sequencing, DGGE, and whole-cell hybridisation of 16S rRNA genes. Sequences of heterotrophic microorganisms belonging to the genera Marinitoga,... |
| Tipo: Text |
Palavras-chave: Metabolic interactions; 16S rRNA gene; Thermophiles; Bioreactor; Continuous enrichment cultures; Deep sea hydrothermal vent; Microbial diversity. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3885.pdf |
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| Postec, Anne; Urios, Laurent; Lesongeur, Francoise; Ollivier, Bernard; Querellou, Joel; Godfroy, Anne. |
| The microflora developing during a continuous enrichment culture from a hydrothermal chimney sample was investigated by molecular methods. The culture was performed in a gas-lift bioreactor under anaerobic conditions, at 90 degrees C and pH 6.5, on a complex medium containing sulfur as the terminal electron acceptor. Archaeal and bacterial diversity was studied. Microorganisms affiliated with the genera Pyrococcus, Marinitoga, and Bacillus were detected through DGGE analysis of 16S rDNA. Additional sequences phylogenetically related to Thermococus and epsilon-Proteobacteria were detected by cloning and sequencing of 16S rDNA from two samples of the enrichment culture. In comparison, the sequences retrieved from cloning analysis from an enrichment culture... |
| Tipo: Text |
Palavras-chave: Sequence alignment; Anaerobic digester; Thermotogales; Thermophile; Deep sea vent. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-364.pdf |
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| Registros recuperados: 42 | |
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