Consulta: creatorFacets:"Roussel, Erwan"
Registros recuperados: 21
Data/hora: 09/06/2024 04:15:04

Survival of Desulfotomaculum spores from estuarine sediments after serial autoclaving and high-temperature exposure
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: O'Sullivan, Louise A.; Roussel, Erwan; Weightman, Andrew J.; Webster, Gordon; Hubert, Casey R. J.; Bell, Emma; Head, Ian; Sass, Henrik; Parkes, R. John.
Bacterial spores are widespread in marine sediments, including those of thermophilic, sulphate-reducing bacteria, which have a high minimum growth temperature making it unlikely that they grow in situ. These Desulfotomaculum spp. are thought to be from hot environments and are distributed by ocean currents. Their cells and spores upper temperature limit for survival is unknown, as is whether they can survive repeated high-temperature exposure that might occur in hydrothermal systems. This was investigated by incubating estuarine sediments significantly above (40–80 °C) maximum in situ temperatures (~23 °C), and with and without prior triple autoclaving. Sulphate reduction occurred at 40–60 °C and at 60 °C was unaffected by autoclaving. Desulfotomaculum sp....
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00216/32759/31181.pdf

New Insights into the Ecology and Physiology of Methanomassiliicoccales from Terrestrial and Aquatic Environments
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cozannet, Marc; Borrel, Guillaume; Roussel, Erwan; Moalic, Yann; Allioux, Maxime; Sanvoisin, Amandine; Toffin, Laurent; Alain, Karine.
Members of the archaeal order Methanomassiliicoccales are methanogens mainly associated with animal digestive tracts. However, environmental members remain poorly characterized as no representatives not associated with a host have been cultivated so far. In this study, metabarcoding screening combined with quantitative PCR analyses on a collection of diverse non-host-associated environmental samples revealed that Methanomassiliicoccales were very scarce in most terrestrial and aquatic ecosystems. Relative abundance of Methanomassiliicoccales and substrates/products of methanogenesis were monitored during incubation of environmental slurries. A sediment slurry enriched in Methanomassiliicoccales was obtained from a freshwater sample. It allowed the...
Tipo: Text
Palavras-chave: Methanomassiliicoccales; Cultivation; Methyl-compounds; Environmental cluster; Networks.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00665/77716/79808.pdf

Archaeal communities associated with shallow to deep subseafloor sediments of the New Caledonia Basin
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan; Sauvadet, Anne-laure; Chaduteau, Carine; Fouquet, Yves; Charlou, Jean-luc; Prieur, Daniel; Cambon, Marie-anne.
P&gt;The distribution of the archaeal communities in deep subseafloor sediments [0-36 m below the seafloor (mbsf)] from the New Caledonia and Fairway Basins was investigated using DNA- and RNA-derived 16S rRNA clone libraries, functional genes and denaturing gradient gel electrophoresis (DGGE). A new method, Co-Migration DGGE (CM-DGGE), was developed to access selectively the active archaeal diversity. Prokaryotic cell abundances at the open-ocean sites were on average similar to 3.5 times lower than at a site under terrestrial influence. The sediment surface archaeal community (0-1.5 mbsf) was characterized by active Marine Group 1 (MG-1) Archaea that co-occurred with ammonia monooxygenase gene (amoA) sequences affiliated to a group of uncultured...
Tipo: Text
Palavras-chave: Marine subsurface sediments; Sea floor biosphere; Gradient gel electrophoresis; Microbial communities; Molecular diversity; Anaerobic oxidation; Sequence alignment; Phylogenetic trees; Extracellular DNA; Methane hydrate.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6801.pdf

Microbial diversity associated with the hydrothermal shrimp Rimicaris exoculata gut and occurrence of a resident microbial community
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Durand, Lucile; Zbinden, Magali; Cueff-gauchard, Valerie; Duperron, Sebastien; Roussel, Erwan; Shillito, Bruce; Cambon-bonavita, Marie-anne.
Rimicaris exoculata dominates the megafauna of several Mid-Atlantic Ridge hydrothermal sites. Its gut is full of sulphides and iron-oxide particles and harbours microbial communities. Although a trophic symbiosis has been suggested, their role remains unclear. In vivo starvation experiments in pressurized vessels were performed on shrimps from Rainbow and Trans-Atlantic Geotraverse sites in order to expel the transient gut contents. Microbial communities associated with the gut of starved and reference shrimps were compared using 16S rRNA gene libraries and microscopic observations (light, transmission and scanning electron microscopy and FISH analyses). We show that the gut microbiota of shrimps from both sites included mainly Deferribacteres, Mollicutes,...
Tipo: Text
Palavras-chave: Deferribacteres; Midgut epibiosis; Mollicutes; Proteobacteria; Rimicaris exoculata; Starvation experiment.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00000/11142/7919.pdf

New insigths on the metabolic diversity among the epibiotic microbial communitiy of the hydrothermal shrimp Rimicaris exoculata
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Zbinden, M; Shillito, B; Le Bris, Nadine; De Montlaur, C; Roussel, Erwan; Guyot, F; Gaill, F; Cambon-bonavita, Marie-anne.
The Rimicaris exoculata dominates the megafauna of some of the Mid Atlantic ridge hydrothermal vent sites. This species harbors a rich community of bacterial epibionts inside its gill chamber. Literature data indicate that a single 16S rRNA phylotype dominates this epibiotic community, and is assumed to be a sulfide-oxidizing bacteria. However attempts Of Cultivation were not successful and did not allow to confirm it. The aim of our study was to test the hypothesis of sulfide oxidation in the gill chamber, by a multidisciplinary approach, using in vivo experiments at in situ pressure in the presence of sulfide, microscopic observations and a molecular survey. Morphology of microorganisms, before and after treatment, was analyzed to test the effect of...
Tipo: Text
Palavras-chave: Sulfur; Methane; Iron; Intracellular granules; Hydrothermal vent shrimp; High pressure experiments.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4563.pdf

Subseafloor archaeal communities: from the surface to a deep hot biosphere?
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan.
The sub-seafloor biosphere may contain two thirds of Earth's total prokaryotic biomass. The large and active microbial populations buried in the sub-seafloor play a key role in global biogeochemical cycles. However, little is known about these prokaryotic communities. The depth limit of this sub-seafloor biosphere is still unreached, and elevated temperatures as well as insufficient energy sources are the likely factors limiting life at depth. Interestingly, archaeal communities with unknown physiologies and no cultured relatives seem to have a key role in deep marine sediments and hydrothermal ecosystems.  As most deep biosphere microorganisms detected so far have been extremely resistant to cultivation, molecular approaches remain to date the most...
Tipo: Text
Palavras-chave: Sediment; Hydrothermal system; Ultramafic; CM DGGE; DGGE; PmoA; DsrA; McrA; AmoA; 16SrRNA; Bacteria; Archaea; Deep biosphere; Sédiment; Écosystème hydrothermal; Ultramafique; CM DGGE; DGGE; PmoA; DsrA; McrA; AmoA; 16SrRNA; Bacteria; Archaea; Biosphère profonde.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-4630.pdf

Phylogenetic and Functional Diversity of Microbial Communities Associated with Subsurface Sediments of the Sonora Margin, Guaymas Basin
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vigneron, Adrien; Cruaud, Perrine; Roussel, Erwan; Pignet, Patricia; Caprais, Jean-claude; Callac, Nolwenn; Ciobanu, Maria Cristina; Godfroy, Anne; Cragg, Barry A.; Parkes, John R.; Van Nostrand, Joy D.; He, Zhili; Zhou, Jizhong; Toffin, Laurent.
Subsurface sediments of the Sonora Margin (Guaymas Basin), located in proximity of active cold seep sites were explored. The taxonomic and functional diversity of bacterial and archaeal communities were investigated from 1 to 10 meters below the seafloor. Microbial community structure and abundance and distribution of dominant populations were assessed using complementary molecular approaches (Ribosomal Intergenic Spacer Analysis, 16S rRNA libraries and quantitative PCR with an extensive primers set) and correlated to comprehensive geochemical data. Moreover the metabolic potentials and functional traits of the microbial community were also identified using the GeoChip functional gene microarray and metabolic rates. The active microbial community structure...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00203/31408/29801.pdf

Methanococcoides
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: L'Haridon, Stephane; Toffin, Laurent; Roussel, Erwan.
Me.tha.no.coc.co'i.des. Gr. adj. suff. ‐oides similar to; N.L. neut. n. Methanococcoides organism similar to Methanococcus. Euryarchaeota / Methanomicrobia / Methanosarcinales / Methanosarcinaceae / Methanococcoides The genus Methanococcoides comprises four species, Methanococcoides methylutens, Methanococcoides burtonii, Methanococcoides alaskense, and Methanococcoides vulcani. Cells are irregular cocci, 0.5–3 μm in diameter, occurring singly or in pairs, and may be motile. Clumps of cells can also observed. Cells exhibit a blue‐green autofluorescence under UV illumination. The cell wall consists of a very thin protein S‐layer, approximately 10‐nm thick. Susceptible to lysis by hypotonic or detergent shock. Eurypsychrophilic to mesophilic. Strict...
Tipo: Text
Palavras-chave: Anaerobe; Psychrophile; Mesophile; Methyl compound reduction; Marine anoxic sediment; Deep‐sea mud volcano; Cold seeps.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00614/72595/74852.pdf

Complex coupled metabolic and prokaryotic community responses to increasing temperatures in anaerobic marine sediments: critical temperatures and substrate changes
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan; Cragg, Barry A.; Webster, Gordon; Sass, Henrik; Tang, Xiaohong; Williams, Angharad S.; Gorra, Roberta; Weightman, Andrew J.; Parkes, R. John.
The impact of temperature (0 - 80°C) on anaerobic biogeochemical processes and prokaryotic communities in marine sediments (tidal flat) was investigated in slurries for up to 100 days. Temperature had a non-linear effect on biogeochemistry and prokaryotes with rapid changes over small temperature intervals. Some activities (e.g. methanogenesis) had multiple “windows” within a large temperature range (~10 - 80°C). Others, including acetate oxidation, had maximum activities within a temperature zone, which varied with electron acceptor (metal oxide [up to ~34°C] and sulphate [up to ~50°C]). Substrates for sulphate reduction changed from predominantly acetate below, and H2 above, a 43°C critical temperature; along with changes in activation energies and types...
Tipo: Text
Palavras-chave: Sediment; Temperature; Anaerobic processes; Chemoorganotrophic; Chemolithotrophic; Mineralisation; Sulphate reduction; Methanogenesis; Acetogenesis.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00273/38464/36883.pdf

Archaeal Methane Cycling Communities Associated with Gassy Subsurface Sediments of Marennes-Oleron Bay (France)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan; Sauvadet, Anne Laure; Allard, Jonathan; Chaduteau, Carine; Richard, Pierre; Cambon Bonavita, Marie-anne; Chaumillon, Eric.
In Marennes-Oleron Bay, a macro-tidal bay located on the French Atlantic coast, kilometer-scale acoustic turbidity reveals an accumulation of free gas in the sediment. Large concentrations of organic matter and rapid sedimentation rates provide ideal settings for biogenic methane cycling. We integrate seismic, sedimentologic, biogeochemical and molecular genetic approaches to determine whether microbial methane cycling is involved in this process. Here we show that the acoustic turbidity upper boundary matched with X-ray facies displaying fissures with the highest methane concentrations, demonstrating the existence of methane bubbles in the sediment. 16S rRNA and mcrA gene clone libraries were dominated by sequences affiliated to the three known ANME...
Tipo: Text
Palavras-chave: Sediment; Methane; McrA; 16S rRNA; Archaea.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6165.pdf

Glycine betaine as a direct substrate for methanogens (Methanococcoides spp.)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Watkins, Andrew J.; Roussel, Erwan; Parkes, R. John; Sass, Henrik.
Nine marine methanogenic Methanococcoides strains, including the type strains of M. methylutens, M. burtonii and M. alaskense, were tested for the utilization of N-methylated glycines. Three strains (NM1, PM2 and MKM1) used glycine betaine (N,N,N-trimethylglycine) as a substrate for methanogenesis, partially demethylating it to N,N-dimethylglycine, whereas none of the strains used N,N-dimethylglycine or sarcosine (N-methylglycine). Growth rates and growth yields per mol of substrate with glycine betaine (3.96 g dw per mol) were similar to those with trimethylamine (4.11 g dw per mol). However, as glycine betaine is only partially demethylated, the yield per methyl group was significantly higher than with trimethylamine. If glycine betaine and...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00161/27235/25443.pdf

Extending the sub-sea-floor biosphere
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan; Cambon-bonavita, Marie-anne; Querellou, Joel; Cragg, B; Webster, G; Prieur, D; Parkes, R.
Sub-sea-floor sediments may contain two-thirds of Earth's total prokaryotic biomass. However, this has its basis in data extrapolation from ~500-meter to 4-kilometer depths, whereas the deepest documented prokaryotes are from only 842 meters. Here, we provide evidence for low concentrations of living prokaryotic cells in the deepest (1626 meters below the sea floor), oldest (111 million years old), and potentially hottest (~100°C) marine sediments investigated. These Newfoundland margin sediments also have DNA sequences related to thermophilic and/or hyperthermophilic Archaea. These form two unique clusters within Pyrococcus and Thermococcus genera, suggesting unknown, uncultured groups are present in deep, hot, marine sediments (~54° to 100°C). Sequences...
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4209.pdf

Comparison of microbial communities associated with three Atlantic ultramafic hydrothermal systems
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roussel, Erwan; Konn, Cecile; Charlou, Jean-luc; Donval, Jean-pierre; Fouquet, Yves; Querellou, Joel; Prieur, Daniel; Cambon-bonavita, Marie-anne.
The distribution of Archaea and methanogenic, methanotrophic and sulfate-reducing communities in three Atlantic ultramafic-hosted hydrothermal systems (Rainbow, Ashadze, Lost City) was compared using 16S rRNA gene and functional gene (mcrA, pmoA and dsrA) clone libraries. The overall archaeal community was diverse and heterogeneously distributed between the hydrothermal sites and the types of samples analyzed (seawater, hydrothermal fluid, chimney and sediment). The Lost City hydrothermal field, characterized by high alkaline warm fluids (pH&gt;11; T&lt;95 °C), harbored a singular archaeal diversity mostly composed of unaffiliated Methanosarcinales. The archaeal communities associated with the recently discovered Ashadze 1 site, one of the deepest active...
Tipo: Text
Palavras-chave: Archaea; Hydrothermal vent; Mid-Atlantic Ridge; 16S rRNA gene; Sediment; Ultramafic.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00067/17836/15573.pdf

Thermococcus piezophilus sp. nov., a novel hyperthermophilic and piezophilic archaeon with a broad pressure range for growth, isolated from a deepest hydrothermal vent at the Mid-Cayman Rise
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Dalmasso, Cecile; Oger, Philippe; Selva, Gwendoline; Courtine, Damien; L'Haridon, Stephane; Garlaschelli, Alexandre; Roussel, Erwan; Miyazaki, Junichi; Reveillaud, Julie; Jebbar, Mohamed; Takai, Ken; Maignien, Lois; Alain, Karine.
A novel strictly anaerobic, hyperthermophilic archaeon, designated strain CDGST, was isolated from a deep-sea hydrothermal vent in the Cayman Trough at 4964 m water depth. The novel isolate is obligate anaerobe and grows chemoorganoheterotrophically with stimulation of growth by sulphur containing compounds. Its growth is optimal at 75 °C, pH 6.0 and under a pressure of 50 MPa. It possesses the broadest hydrostatic pressure range for growth that has ever been described for a microorganism. Its genomic DNA G + C content is 51.11 mol%. The novel isolate belongs to the genus Thermococcus. Phylogenetic analyses indicated that it is most closely related to Thermococcus barossii DSM17882T based on its 16S rRNA gene sequence, and to ‘Thermococcus onnurineus’ NA1...
Tipo: Text
Palavras-chave: Thermococcus; Piezophile; Hydrothermal vent; Cayman Trough.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00348/45949/45655.pdf

Cultivation of an immobilized (hyper)thermophilic marine microbial community in a bioreactor
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Redescription and phylogenetic analyses of Durchoniella spp. (Ciliophora, Astomatida) associated with the polychaete Cirriformia tentaculata (Montagu, 1808)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sauvadet, Anne-laure; Lynn, Denis H.; Roussel, Erwan; Le Panse, Sophie; Bigeard, Estelle; Schrevel, Joseph; Guillou, Laure.
Microscopic and phylogenetic analyses were performed on endocommensal astome ciliates retrieved from the middle intestine of a marine cirratulid polychaete, Cirriformia tentaculata, collected in the bay of Roscoff (English Channel, Northwest French coast) and on the Southwest English coast. Three morphotypes of the astome genus Durchoniella were identified, two corresponding to described species (the type species Durchoniella brasili (Léger and Duboscq, 1904) de Puytorac, 1954 and Durchoniella legeriduboscqui de Puytorac, 1954) while a third morphotype remains undescribed. Their small subunit (SSU) rRNA gene sequences showed at least 97.2% identity and phylogenetic analyses grouped them at the base of the subclass Scuticociliatia (Oligohymenophorea), as a...
Tipo: Text
Palavras-chave: Astomatida; Ciliophora; Cirratulidae; Endocytoplasmic bacteria; Microscopy; Molecular phylogeny.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00392/50312/50990.pdf

Organic, Gas, and Element Geochemistry of Hydrothermal Fluids of the Newly Discovered Extensive Hydrothermal Area in the Wallis and Futuna Region (SW Pacific)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Konn, Cecile; Donval, Jean-pierre; Guyader, Vivien; Roussel, Erwan; Fourre, E.; Jean-baptiste, P.; Pelleter, Ewan; Charlou, Jean-luc; Fouquet, Yves.
Two newly discovered hydrothermal vent fields of the Wallis and Futuna region, Kulo Lasi and Fatu Kapa, were sampled for fluid geochemistry. A great geochemical diversity was observed and assigned to the diversity of lithologies as well as the occurrence of various processes. Kulo Lasi fluids likely formed by interaction with fresh volcanic rocks, phase separation, and mixing with magmatic fluid. Conversely, the geochemistry of the Fatu Kapa fluids would be mostly due to water/felsic lavas reactions. In terms of organic geochemistry, fluids from both fields were found to be enriched in formate, acetate, and semivolatile organic compounds (SVOCs): n-alkanes, n-fatty acids, and polyaromatic hydrocarbons (PAHs). Concentrations of SVOCs reached a few ppb at...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00431/54245/55571.pdf

Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Parkes, Ronald John; Berlendis, Sabrina; Roussel, Erwan; Bahruji, Hasiliza; Webster, Gordon; Oldroyd, Anthony; Weightman, Andrew J.; Bowker, Michael; Davies, Philipp R; Sass, Henrik.
Microbial populations exist to great depths on Earth, but with apparently insufficient energy supply. Earthquake rock fracturing produces H2 from mechanochemical water splitting, however, microbial utilization of this widespread potential energy source has not been directly demonstrated. Here, we show experimentally that mechanochemically generated H2 from granite can be directly, long‐term, utilized by a CH4 producing microbial community. This is consistent with CH4 formation in subsurface rock fracturing in the environment. Our results not only support water splitting H2 generation as a potential deep biosphere energy source, but as an oxidant must also be produced, they suggest that there is also a respiratory oxidant supply in the subsurface which is...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00483/59444/62283.pdf

Diversity and distribution of methane-oxidizing microbial communities associated with different faunal assemblages in a giant pockmark of the Gabon continental margin
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cambon-bonavita, Marie-anne; Nadalig, Thierry; Roussel, Erwan; Delage, Eloise; Duperron, Sebastien; Caprais, Jean-claude; Boetius, A.; Sibuet, Myriam.
A giant 800-m-diameter pockmark named REGAB was discovered on the Gabon continental margin actively emitting methane at a water depth of 3200 m. The microbial diversity in sediments from four different assemblages of chemosynthetic organisms, Mytilidae, Vesicomyidae, Sibogliniclae and a bacterial mat, was investigated using comparative 16S rRNA gene sequence analysis. Aggregates of anaerobic methanotrophic archaea (ANME-2) and bacteria of the Desulfosarcina/Desulfococcus cluster were found in all four chemosynthetic habitats. Fluorescence in situ hybridization targeting the ANME-2/Desulfosarcina/Desulfococcus aggregates showed their presence few centimeters (3-5cm) below the surface of sediment. 16S rRNA gene sequences from all known marine ANME groups...
Tipo: Text
Palavras-chave: Microbial phylogeny; Faunal assemblage; Cold seep; Chemosynthetic ecosystems; AOM; REGAB.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/2009/publication-7298.pdf

Evidence of active methanogen communities in shallow sediments of the Sonora Margin cold seeps
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00256/36737/35338.pdf

A review of prokaryotic populations and processes in sub-seafloor sediments, including biosphere:geosphere interactions
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Parkes, R. John; Cragg, Barry; Roussel, Erwan; Webster, Gordon; Weightman, Andrew; Sass, Henrik.
A general review of the sub-seafloor biosphere is presented. This includes an update and assessment of prokaryotic cell distributions within marine sediments, current deepest 1922 m, and the impact of this on global sub-seafloor biomass estimates. These global estimates appear relatively robust to different calculation approaches and our updated estimate is 5.39 × 1029 cells, taking into consideration new data from very low organic matter South Pacific Gyre sediments. This is higher than other recent estimates, which is justified as several sediments, such as gas hydrate deposits and oil reservoirs, can have elevated cell concentrations. The proposed relationship between elevated cell concentrations and Milankovitch Cycles in sequential diatom rich layers...
Tipo: Text
Palavras-chave: Sub-seafloor biosphere; Marine microbiology; Prokaryotic diversity; Dark energy; Biosphere:geosphere interactions.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00178/28965/27711.pdf