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| Registros recuperados: 13 | |
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| Rassmann, Jens; Eitel, Eryn M.; Lansard, Bruno; Cathalot, Cecile; Brandily, Christophe; Taillefert, Martial; Rabouille, Christophe. |
| Estuarine regions are generally considered a major source of atmospheric CO2, as a result of the high organic carbon (OC) mineralization rates in their water column and sediments. Despite this, the intensity of anaerobic respiration processes in the sediments tempered by the reoxidation of reduced metabolites near the sediment–water interface controls the flux of benthic alkalinity. This alkalinity may partially buffer metabolic CO2 generated by benthic OC respiration in sediments. Thus, sediments with high anaerobic respiration rates could contribute less to local acidification than previously thought. In this study, a benthic chamber was deployed in the Rhône River prodelta and the adjacent continental shelf (Gulf of Lion, northwestern Mediterranean) in... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00600/71163/69492.pdf |
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| Pastor, Lucie; Toffin, Laurent; Decker, Carole; Olu, Karine; Cathalot, Cecile; Lesongeur, Francoise; Caprais, Jean-claude; Bessette, Sandrine; Brandily, Christophe; Taillefert, M.; Rabouille, C.. |
| Geochemical profiles (SO42-, H2S, CH4, δ13CH4) and phylogenetic diversity of Archaea and Bacteria from two oceanographic cruises dedicated to the lobes sediments of the Congo deep-sea fan are presented in this paper. In this area, organic-rich turbidites reach 5000 m and allow the establishment of patchy cold-seep-like habitats including microbial mats, reduced sediments, and vesicomyid bivalves assemblages. These bivalves live in endosymbiosis with sulfur-oxidizing bacteria and use sulfides to perform chemosynthesis. In these habitats, unlike classical abyssal sediments, anoxic processes are dominant. Total oxygen uptake fluxes and methane fluxes measured with benthic chambers are in the same range as those of active cold-seep environments, and oxygen is... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48767/49164.pdf |
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| Croguennec, Claire; Ruffine, Livio; Dennielou, Bernard; Baudin, Francois; Caprais, Jean-claude; Guyader, Vivien; Bayon, Germain; Brandily, Christophe; Le Bruchec, Julie; Bollinger, Claire; Germain, Yoan; Droz, Laurence; Babonneau, Nathalie; Rabouille, Christophe. |
| On continental margins, sulfate reduction occurs within the sedimentary column. It is coupled with the degradation of organic matter and the anaerobic oxidation of methane. These processes may be significantly disturbed by sedimentary events, leading to transient state profiles for the involved chemical species. Yet, little is known about the impact of turbidity currents and mass wasting on the migration of chemical species and the redox reactions in which they are involved. Due to its connection to the River, the Congo deep-sea fan continuously receives huge amount of organic matter-rich sediments primarily transported by turbidity currents, which impact on the development of the associated ecosystems (Rabouille et al., 2016). Thus, it is well suited to... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00363/47410/47403.pdf |
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| Lelchat, Florian; Cozien, Joelle; Le Costaouec, Tinaig; Brandily, Christophe; Schmitt, Sophie; Baudoux, Anne-claire; Colliec-jouault, Sylvia; Boisset, Claire. |
| Alteromonas macleodii subsp. fijiensis biovar deepsane is a deep-sea ecotype exopolysaccharide-producing bacteria isolated from the polychaete annelid Alvinella pompejana. The high molecular weight biopolymer HYD657 produced by this strain, is the first marine exopolysaccharide (EPS) to be commercialized for cosmetic use. Depolymerization methods are necessary to elucidate the complete structure of this EPS and to generate potentially bioactive oligosaccharides. Enzymatic methods are useful for elucidating polysaccharide structure because they specifically cleave glycosidic bonds and do not require harsh chemical conditions. The HYD657 EPS is structurally complex and no commercially available enzymes are able to effectively degrade it. Here, we present the... |
| Tipo: Text |
Palavras-chave: Marine Alteromonas macleodii sp strain; Bacterial exopolysaccharides; Microbial extracellular enzymes; Endogenous enzymatic degradation. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00240/35129/33893.pdf |
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| Portail, Marie; Brandily, Christophe; Cathalot, Cecile; Colaco, Ana; Gelinas, Yves; Husson, Berengere; Sarradin, Pierre-marie; Sarrazin, Jozee. |
| The assessment and comparison of food webs across various hydrothermal vent sites can enhance our understanding of ecological processes involved in the structure and function of biodiversity. The Menez Gwen, Lucky Strike and Rainbow vent fields are located on the Azores triple junction of the Mid-Atlantic Ridge. These fields have distinct depths (from 850 to 2320 m) and geological contexts (basaltic and ultramafic), but share similar faunal assemblages defined by the presence of foundation species that include Bathymodiolus azoricus, alvinocarid shrimp and gastropods. We compared the food webs of 13 faunal assemblages at these three sites using carbon and nitrogen stable isotope analyses (SIA). Results showed that photosynthesis-derived organic matter is a... |
| Tipo: Text |
Palavras-chave: Mid-Atlantic Ridge; Hydrothermal vents; Food webs; Stable isotopes; Functional traits. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00414/52551/53732.pdf |
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| Fontanier, Christophe; Garnier, Eline; Brandily, Christophe; Dennielou, Bernard; Bichon, S.; Gayet, Nicolas; Eugene, Thibaut; Rovere, Mickael; Gremare, A.; Deflandre, B.. |
| Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530–3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30 mm) in sediment. Interestingly, foraminiferal species... |
| Tipo: Text |
Palavras-chave: Mozambique Channel; Foraminifera; Diversity; Microhabitat; Organic matter. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00344/45505/45057.pdf |
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| Bellec, Laure; Cambon-bonavita, Marie-anne; Durand, Lucile; Aube, Johanne; Gayet, Nicolas; Sandulli, Roberto; Brandily, Christophe; Zeppilli, Daniela. |
| Shallow-water hydrothermal vents are widespread, especially in the Mediterranean Sea, owing to the active volcanism of the area. Apart free microbial communities’ investigations, few biological studies have been leaded yet. Investigations of microbial communities associated with Nematoda, an ecologically important group in sediments, can help to improve our overall understanding of these ecosystems. We used a multidisciplinary-approach, based on microscopic observations (scanning electron microscopy: SEM and Fluorescence In Situ Hybridization: FISH) coupled with a molecular diversity analysis using metabarcoding, based on the 16S rRNA gene (V3-V4 region), to characterize the bacterial community of a free-living marine nematode and its environment, the... |
| Tipo: Text |
Palavras-chave: Nematode; Shallow-water hydrothermal vent; Sulfur-oxidizing bacteria; Iron cycle; Zetaproteobacteria. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75544/76449.pdf |
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| Pastor, Lucie; Brandily, Christophe; Schmidt, S.; Miramontes, E.; Péron, Maela; Appere, Dennis; Chéron, Sandrine; Boissier, Audrey; Jouet, Gwenael. |
| The NW Madagascar continental margin receives high loads of terrigenous particulate organic matter during the wet season and especially linked to extreme events, originating from two major rivers, the Betsiboka and the Mahavavy Rivers. This particulate matter contains a high content of iron minerals from the weathering of red ferruginous/ferralitic soils of Madagascar. The presence of pockmarks, i.e. gas or fluid expulsion features on the continental slope, testifies to past/present methane migration through the sedimentary column, associated with early diagenetic processes. This study globally aims at deciphering the interactions between episodic sedimentation and geochemical processes influenced by fluids upward migration, using a sediment trap mooring... |
| Tipo: Text |
Palavras-chave: Episodic sedimentation; Madagascar margin; Betsiboka river; Mahavavy river; Progradation; Methane; Geochemistry; Sediment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73964/73323.pdf |
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| Chalkiadakis, Eletherios; Dufourcq, R.; Schmitt, Sophie; Brandily, Christophe; Kervarec, N.; Coatanea, Denis; Amir, H.; Loubersac, Lionel; Chanteau, S.; Guezennec, Jean; Dupont-rouzeyrol, M.; Simon-colin, Christelle. |
| Aims Exopolysaccharides (EPS) are industrially valuable molecules with numerous useful properties. This study describes the techniques used for the identification of a novel Vibrio bacterium and preliminary characterization of its EPS. Methods and Results Bioprospection in marine intertidal areas of New Caledonia followed by screening for EPS producing brought to selection of the isolate NC470. Phylogenetic analysis (biochemical tests, gene sequencing and DNADNA relatedness) permitted to identify NC470 as a new member of the Vibrio genus. The EPS was produced in batch fermentation, purified using the ultrafiltration process and analysed by colorimetry, Fourier Transform Infrared spectroscopy, gas chromatography, Nuclear Magnetic Resonance and HPLC-size... |
| Tipo: Text |
Palavras-chave: Biopolymers; Biotechnology; Exopolysaccharide; Fermentation biotechnology. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00144/25501/24036.pdf |
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| Ruffine, Livio; Germain, Yoan; Polonia, Alina; De Prunele, Alexis; Croguennec, Claire; Donval, Jean-pierre; Pitel-roudaut, Mathilde; Ponzevera, Emmanuel; Caprais, Jean-claude; Brandily, Christophe; Grall, Celine; Bollinger, Claire; Geli, Louis; Gasperini, Luca. |
| Within the Sea of Marmara, the highly active North Anatolian Fault (NAF) is responsible for major earthquakes (Mw>=7), and acts as a pathway for fluid migration from deep sources to the seafloor. This work reports on pore water geochemistry from three sediment cores collected in the Gulfs of Izmit and Gemlik, along the Northern and the Middle strands of the NAF, respectively. The resulting data set shows that anaerobic oxidation of methane (AOM) is the major process responsible for sulfate depletion in the shallow sediment. In the Gulf of Gemlik, depth concentration profiles of both sulfate and alkalinity exhibit a kink-type profile. The Sulfate Methane Transition Zone (SMTZ) is located at moderate depth in the area. In the Gulf of Izmit, the low... |
| Tipo: Text |
Palavras-chave: Anaerobic oxidation of methane; North Anatolian Fault; Pore water geochemistry; Sea of Marmara; Seismic activity. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00272/38339/36570.pdf |
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| Fontanier, Christophe; Sakai, Saburo; Toyofuku, Takashi; Garnier, Eline; Brandily, Christophe; Eugene, Thibaut; Deflandre, Bruno. |
| Oxygen and carbon isotopes (δ18O and δ13C) have been investigated in carbonate tests of deep-sea foraminifera living in the Mozambique Channel (eastern Africa) to understand how environmental constraints (e.g., organic matter, oxygenation) control the intra- and interspecific variability of isotopic signatures. 197 living individuals, including eight different species, from various microhabitats within the sediment were sorted from sediment samples gathered at two stations on the Malagasy upper slope. Results show that the δ18O values of foraminiferal taxa were not controlled by microhabitat pattern. They presented tremendous and intriguing intraspecific variability that is not explained by the classical ontogenetic effect. The δ13C values of infaunal... |
| Tipo: Text |
Palavras-chave: Oxygen and carbon isotopes; Deep-sea foraminifera; Organic matter; Oxygenation; Microhabitat. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00357/46831/46979.pdf |
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| Rabouille, C.; Olu, Karine; Baudin, F.; Khripounoff, Alexis; Dennielou, Bernard; Arnaud-haond, Sophie; Babonneau, Nathalie; Bayle, Christophe; Beckler, J.; Bessette, Sandrine; Bombled, B.; Bourgeois, S.; Brandily, Christophe; Caprais, Jean-claude; Cathalot, Cecile; Charlier, K.; Corvaisier, R.; Croguennec, Chantal; Cruaud, Perrine; Decker, Carole; Droz, L.; Gayet, Nicolas; Godfroy, Anne; Hourdez, S.; Le Bruchec, J.; Saout, Johan; Le Saout, Marie-helene; Lesongeur, Francoise; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, Olivier; Noel, Philippe; Pastor, Lucie; Picot, M.; Pignet, Patricia; Pozzato, L.; Pruski, A. M.; Rabiller, Manuella; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, Philippe; Ruesch, Blandine; Ruffine, Livio; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, Arunima; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-laborde, N.; Toffin, Laurent; Tourolle, Julie; Toussaint, F.; Vetion, G.; Jouanneau, J. M.; Bez, M.. |
| The presently active region of the Congo deep-sea fan (around 330 000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700–5100 m water depth and 750–800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the... |
| Tipo: Text |
Palavras-chave: Chemosynthetic habitats; Congo deep-sea fan; Fine sediment; Sedimentation rate; Seafloor morphology; Turbidite; Vesicomyidae. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00335/44580/44298.pdf |
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| Lelchat, Florian; Cerantola, Stephane; Brandily, Christophe; Colliec-jouault, Sylvia; Baudoux, Anne-claire; Ojima, Takao; Boisset, Claire. |
| We have studied the exopolysaccharide produced by Cobetia marina DSMZ 4741, a marine bacterium isolated from coastal seawater. This strain is able to produce a polysaccharide in presence of carbon sources as glucose, mannitol and alginate. The maximum production occurs in aerobic condition, during the end of the exponential phase. The polymer is a non-viscous, acidic heteropolysaccharide of 270 kDa constituted of a repeating unit of: →2)-β-D-Ribf-(1→4)-[7,8-O-(Pyr)]-α-D-KDOp-(2→ This kind of chemical structure is generally related to K-antigen polysaccharide of pathogenic Escherichia coli strains. This is the first time this type of EPS is described from a marine bacterium. Moreover the polysaccharide exhibits a pyruvate substitution on its... |
| Tipo: Text |
Palavras-chave: Bacterial exopolysaccharides; K-antigen; Cobetia marina; KDO; Marine polysaccharide. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00254/36494/35038.pdf |
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| Registros recuperados: 13 | |
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