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Registros recuperados: 29 | |
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Simon-colin, Christelle; Raguenes, Gerard; Crassous, Philippe; Moppert, X; Guezennec, Jean. |
Pseudomonasguezennei biovar. tikehau was isolated from a microbial mat on the atoll of Tikehau in French Polynesia, and is able to synthesize medium chain length poly-beta-hydroxyalkanaote copolymers when grown on coprah oil. A two-step cultivation process was used and the biosynthesis of PHAs was followed along 52 h by regular culture sampling. The polyester was purified from freeze-dried cells and analysed by nuclear magnetic resonance (NMR), Fourier transform infra red (FTIR), and gas chromatography mass spectrometries. The copolyester produced by P. guezennei biovar. tikehau from coprah oil mainly consisted of saturated monomers, i.e. 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD), and the monomeric composition of the polyester did not change... |
Tipo: Text |
Palavras-chave: Polyhydroxyalkanaote; PHAs; Pseudomonas; "kopara"; Microbial mat. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6119.pdf |
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Guri, Mathieu; Durand, Lucile; Cueff-gauchard, Valerie; Zbinden, Magali; Crassous, Philippe; Shillito, Bruce; Cambon-bonavita, Marie-anne. |
The caridean shrimp Rimicaris exoculata dominates the fauna at several Mid-Atlantic Ridge hydrothermal vent sites. This shrimp has an enlarged gill chamber, harboring a dense ectosymbiotic community of chemoautotrophic bacteria associated with mineral oxide deposits. Until now, their acquisition is not fully understood. At three hydrothermal vent sites, we analyzed the epibionts diversity at different moult stages and also in the first stages of the shrimp life (eggs, hatched eggs (with larvae) and juveniles). Hatched eggs associated with young larvae were collected for the first time directly from gravid females at the Logachev vent site during the Serpentine cruise. An approach using 16S rRNA clone libraries, scanning and transmission electron... |
Tipo: Text |
Palavras-chave: Symbiosis; Larvae; Methanotrophic symbiont; Rimicaris exoculata; Transmission pathways. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00072/18318/15997.pdf |
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Durand, Lucile; Roumagnac, Marie; Cueff-gauchard, Valerie; Jan, Cyrielle; Guri, Mathieu; Tessier, Claire; Haond, Marine; Crassous, Philippe; Zbinden, Magali; Arnaud-haond, Sophie; Cambon-bonavita, Marie-anne. |
Rimicaris exoculata is a deep-sea hydrothermal vent shrimp which enlarged gill chamber houses a complex trophic epibiotic community. Its gut harbours an autochthonous and distinct microbial community. This species dominates hydrothermal ecosystems megafauna along the Mid-Atlantic Ridge, regardless of contrasted geochemical conditions prevailing in them. Here, the resident gut epibiont community at four contrasted hydrothermal vent sites (Rainbow/TAG/Logatchev/Ashadze) was analysed and compiled with previous data to evaluate the possible influence of site location, using 16S rRNA surveys and microscopic observations (TEM, SEM and FISH analyses). Filamentous epibionts inserted between the epithelial cells microvilli were observed on all examined samples.... |
Tipo: Text |
Palavras-chave: Epibiont; Extreme environments; Network analyses; Phylogeography. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00288/39890/38443.pdf |
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Alain, Karine; Pignet, Patricia; Zbinden, M; Quillevere, M; Duchiron, F; Donval, Jean-pierre; Lesongeur, Francoise; Raguenes, Gerard; Crassous, Philippe; Querellou, Joel; Cambon-bonavita, Marie-anne. |
A novel thermophilic, anaerobic, strictly chemoorganoheterotrophic bacterium, designated as AM1114(T), was isolated from a deep-sea hydrothermal vent sample from the East-Pacific Rise (EPR 13degrees N). The cells were long (3-10 mum) rods, motile with peritrichous flagella, and exhibited a Gram-negative cell wall ultrastructure. In the late stationary phase of growth, cells formed an ovoid, refractile, terminal endospore. They grew at 45-65 degreesC inclusive (optimum 55-60 degreesC; doubling time approx. 45 min), at pH 4.5-8.0 inclusive (optimum pH 7.5-8.0) and at sea salt concentrations of 20-60 g l(-1) inclusive (optimum 25-30 g l(-1)). Strain AM1114(T) was an obligately heterotrophic bacterium able to ferment a mixture of 20 amino acids, complex... |
Tipo: Text |
Palavras-chave: Caminicella sporogenes; Clostridiales; Thermophile; Deep sea hydrothermal vent. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-528.pdf |
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Menot, Lenaick; Crassous, Philippe; Desbruyeres, Daniel; Galeron, Joelle; Khripounoff, Alexis; Sibuet, M.. |
In the framework of the deep-sea environmental programme BIOZAIRE (Ifremer-Total), colonization trays were deployed for 283-433 days at three sites along the equatorial West African margin: ZA at 1300-m depth, ZC at 4000-m depth far from the Congo canyon and ZD at 4000-m depth close to the Congo canyon. The experiments aimed at determining the influence of depth and local environmental settings on macrofaunal colonization patterns and organic carbon degradation rates. The trays were filled with glass beads and this artificial substrate was enriched with ground particulate organic matter in a gradient of 0%, 0.34%, 1.02% and 3.43% organic carbon. The highest rates of organic carbon degradation ranged, according to the duration of the experiments, from 1.59... |
Tipo: Text |
Palavras-chave: Diversity; Organic enrichment; Macrofauna; Deep sea; Colonization; Biozaire. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7323.pdf |
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Alain, Karine; Rolland, Sophie; Crassous, Philippe; Lesongeur, Francoise; Zbinden, Magali; Le Gall, Christian; Godfroy, Anne; Page, Antoine; Juniper, S Kim; Cambon-bonavita, Marie-anne; Duchiron, Francis; Querellou, Joel. |
A novel thermophilic, chemolithoautotrophic T bacterium, designated as NE1206(T), was isolated from a Juan de Fuca Ridge hydrothermal vent sample (tubes of the annelid polychaete Paralvinella sulfincola attached to small pieces of hydrothermal chimney). The cells were rod-shaped (1.2-3.5x0.4-0.7 mum), occurring as single motile rods or forming macroscopic aggregates visible as pinkish to brownish streamers. The new isolate was anaerobic. It grew between 50 and 70 degreesC (optimum 60-65 degreesC doubling time approximately 1 h 15 min at 60 degreesC), between pH 5.0 and 7.5 (optimum pH around 6.0-6.5) and at sea salts concentrations between 20 and 40 g l(-1) (optimum 30 g l(-1)). Cells grew chemolithoautotrophically in an H-2/CO2 atmosphere (80/20, v/v; 200... |
Tipo: Text |
Palavras-chave: Thermophile; Nitrate reducing; Lithotroph; Desulfurobacterium crinifex; Deep sea hydrothermal vent; Cell networks. |
Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-663.pdf |
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Khripounoff, Alexis; Crassous, Philippe; Lo Bue, N.; Dennielou, Bernard; Silva Jacinto, Ricardo. |
Current velocities and vertical sediment fluxes in the Var submarine canyon were assessed at three stations respectively at 800 m, 1200 m and 1800 m depth, using moorings deployed for 4 months during winter 2008-2009. During this period, we observed three major sediment gravity flows, all characterized by sudden increases in current velocity that lasted 2-5 h and by downward particle fluxes. Each gravity flow, described using a high frequency current meter and two Acoustic Doppler Current Profiler (75 and 300 kHz ADCP) showed distinctive features. The first event, triggered during a flood of the Var River, was determined to be a hyperpycnal current with a large vertical extent (>100 m high) and relatively low velocity (40 cm s(-1)). The second event,... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00113/22394/20343.pdf |
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Sarradin, Pierre-marie; Lannuzel, D; Waeles, M; Crassous, Philippe; Le Bris, Nadine; Caprais, Jean-claude; Fouquet, Yves; Fabri, Marie-claire; Riso, R. |
The distribution of Fe, Cu, Zn, Pb, Cd between the dissolved (<2 mu m) and the particulate (>2 mu m) fractions was measured after in-situ filtration in two hydrothermal habitats. The total metal concentration ranges exhibit a clear enrichment compared with the seawater concentration, accounting for the hydrothermal input for all the metals considered. Iron is the predominant metal (5-50 mu M) followed by Zn and Cu. Cd and Pb are present at the nM level. At the scale studied, the behavior of temperature, pH and dissolved iron is semi-conservative whereas the other dissolved and particulate metals are characterized by non-conservative patterns. The metal enrichment of the >2 mu m fraction results from the settlement and accumulation of particulate... |
Tipo: Text |
Palavras-chave: Hydrothermal fauna; Habitats; Particulate; Dissolved; Metals. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3830.pdf |
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Gaill, Francoise; Felbeck, Horst; Desbruyeres, Daniel; Lallier, Francois; Toulmond, A.; Alayse, Anne-marie; Briand, Patrick; Brulport, Jean-pierre; Caprais, Jean-claude; Chevaldonne, P.; Coail, Jean-yves; Cosson, R.; Crassous, Philippe; Delachambre, J.; Durif, C.; Echardour, L.; Herve, G.; Hourdez, Stephane; Jollivet, D.; Kerdoncuff, Jacques; Khripounoff, Alexis; Lechaire, J.p.; Pruski, Audrey; Ravaux, Juliette; Sarradin, Pierre-marie; Shillito, Bruce; Toullec, J.y.; Arndt, C.; Fisher, C.; Lutz, Richard; Childress, J.. |
Tipo: Text |
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Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00179/29003/27431.pdf |
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Moppert, Xavier; Le Costaouec, Tinaig; Raguenes, Gerard; Courtois, Anthony; Simon-colin, Christelle; Crassous, Philippe; Costa, Bernard; Guezennec, Jean. |
A bacterium isolated from microbial mats located on a polynesian atoll produced a high molecular weight (3,000 kDa) and highly sulphated exopolysaccharide. Previous studies showed that the chemical structure of this EPS consisted of neutral sugars, uronic acids, and high proportions of acetate and sulphate groups. The copper- and iron-binding ability of the purified pre-treated native EPS was investigated. Results showed that this EPS had a very high affinity for both copper (9.84 mmol g(-1) EPS) and ferrous iron (6.9 mmol g(-1) EPS). Amazingly, this EPS did not show any affinity for either ferric ions or selenium salts. This finding is one of the first steps in assessing the biotechnological potential of this polysaccharide. |
Tipo: Text |
Palavras-chave: Sulphated exopolysaccharide; Microbial mats; Iron; Copper; Binding capacity. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6397.pdf |
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Trinkler, Nolwenn; Bardeau, Jean-francois; Marin, Frederic; Labonne, Maylis; Jolivet, Aurelie; Crassous, Philippe; Paillard, Christine. |
The mineral phase of shell repair in the Manila clam Venerupis philippinarum affected by brown ring disease (BRD) was characterised at various scales and at various stages of shell repair by confocal Raman microspectrometry and scanning electron microscopy. Spherulitic and quadrangular aragonite microstructures associated with polyene pigments were clearly observed. Von Kossa staining showed that at the beginning of shell repair, hemocytes are filled with insoluble calcium carbonate salts in all fluids and then are transported toward the extrapallial fluids and the repair sites. Our analyses suggest that after a Vibrio tapetis attack and BRD deposit some clams rapidly cover the deposit, resulting in a modification in the microstructure, which could be... |
Tipo: Text |
Palavras-chave: Aragonite; Hemocytes; Shell microstructure; Calcium carbonate; Biomineralization; Mollusc; Raman microspectrometry; Scanning electron microscopy. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14065/11301.pdf |
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Alain, Karine; Callac, Nolwenn; Guegan, Marianne; Lesongeur, Francoise; Crassous, Philippe; Cambon-bonavita, Marie-anne; Querellou, Joel; Prieur, Daniel. |
A novel strictly anaerobic, thermophilic, sulfur-reducing bacterium, designated PH1209(T), was isolated from an East Pacific Rise hydrothermal vent (13 degrees N) sample and studied using a polyphasic taxonomic approach. Cells were Gram-negative, motile rods (approx. 1.60x0.40 mu m) with a single polar flagellum. Strain PH1209(T) grew at temperatures between 33 and 65 degrees C (optimum 60 degrees C), from pH 5.0 to 8.0 (optimum 6.0-6.5), and between 2 and 4% (w/v) NaCl (optimum 3%). Cells grew chemolithoautotrophically with H-2 as an energy source, So as an electron acceptor and CO2 as a carbon source. Strain PH1209(T) was also able to use peptone and yeast extract as carbon sources. The G+C content of the genomic DNA was 35 mol%. Phylogenetic: analyses... |
Tipo: Text |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6585.pdf |
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Desbruyeres, Daniel; Alayse, Anne-marie; Antoine, Elisabeth; Barbier, Georges; Barriga, Fjas; Biscoito, Manuel; Briand, Patrick; Brulport, Jean-pierre; Comtet, Thierry; Cornec, Laurence; Crassous, Philippe; Dando, Paul; Fabri, Marie-claire; Felbeck, Horst; Lallier, Francois; Fiala Medioni, Aline; Goncalves, Joao; Menard, Frederic; Kerdoncuff, Jacques; Patching, John; Saldanha, Luis; Sarradin, Pierre-marie. |
Tipo: Text |
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Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00179/29005/27432.pdf |
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Rabouille, C.; Caprais, Jean-claude; Lansard, B.; Crassous, Philippe; Dedieu, K.; Reyss, J. L.; Khripounoff, Alexis. |
A study of organic carbon mineralization from the Congo continental shelf to the abyssal plain through the Congo submarine channel and Angola Margin was undertaken using in situ measurements of sediment oxygen demand as a tracer of benthic carbon recycling. Two measurement techniques were coupled on a single autonomous platform: in situ benthic chambers and microelectrodes, which provided total and diffusive oxygen uptake as well as oxygen microdistributions in porewaters. In addition, sediment trap fluxes, sediment composition (Org-C, Tot-N, CaCO3, porosity) and radionuclide profiles provided measurements of, respectively input fluxes and burial rate of organic and inorganic compounds. The in situ results show that the oxygen consumption on this margin... |
Tipo: Text |
Palavras-chave: Sediment carbon budget; Organic carbon burial; Congo Submarine Canyon; Organic carbon recycling in sediments; In situ oxygen demand. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7316.pdf |
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Khripounoff, Alexis; Vangriesheim, Annick; Crassous, Philippe; Segonzac, Michel; Colaco, Ana; Desbruyeres, Daniel; Barthelemy, Roxane. |
In order to provide information about the export and the distribution of hydrothermal particulate material to the surrounding deep ocean, four moorings were deployed in the vicinity of the hydrothermal Rainbow vent field (Mid-Atlantic Ridge, 36 degrees 14'N, 2250 m depth). The first mooring was a sediment trap with a current meter deployed at 2 m from a chimney of the Rainbow vent field and 1.5 m above the bottom (a.b.) for 16 days. It represented the reference for the initial composition of particles produced by the vent. The total mean mass particle flux (6.9 g m(-2) d(-1)) was distinctly higher than the flux measured at the shallower hydrothermal vents on the MAR segment. This particulate flux showed a high temporal variation at the scale of a few days... |
Tipo: Text |
Palavras-chave: Zooplankton; Biochemistry; Geochemistry; Particle flux; Hydrothermal vent. |
Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-801.pdf |
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Delmail, David; Labrousse, Pascal; Crassous, Philippe; Hourdin, Philippe; Guri, Mathieu; Botineau, Michel. |
A new freshwater epiphytic Prorocentrum species, Prorocentrum rivalis, from the temperate region of the Haute-Vienne, France, is described. This species is the third freshwater species identified among approximately 60 marine Prorocentrum species. This new species is described using scanning electron microscope and phylogenetic analyses by a polyphasic approach (LSU rRNA sequences combined with 9 morphological characters). The phylogenetic analysis attests that P. rivalis is close to other planktonic freshwater species and the freshwater Prorocentrum clade is evolutionarily derived from an epiphytic freshwater prorocentroid ancestor. The unique marine species in the freshwater clade results from an ecophysiological reversion. P. rivalis differs from other... |
Tipo: Text |
Palavras-chave: Prorocentrum rivalis; Epiphytic microalgae; LSU; Phylogeny; Polyphasic approach; SEM. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14601/12235.pdf |
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Registros recuperados: 29 | |
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