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| Registros recuperados: 12 | |
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| Vasseur, Christophe; Bougaran, Gael; Garnier, Matthieu; Hamelin, Jérôme; Leboulanger, Christophe; Le Chevanton, Myriam; Mostajir, Behzad; Sialve, Bruno; Steyer, Jean-philippe; Fouilland, Eric. |
| Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae–bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate)... |
| Tipo: Text |
Palavras-chave: Optimization; Nannochloris; Heterotrophic bacteria; Anaerobic digestion; Bioenergy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00085/19642/17419.pdf |
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| Cadeau, Pierre; Jézéquel, Didier; Leboulanger, Christophe; Fouilland, Eric; Le Floc’h, Emilie; Chaduteau, Carine; Milesi, Vincent; Guélard, Julia; Sarazin, Gérard; Katz, Amandine; D’amore, Sophie; Bernard, Cecile; Ader, Magali. |
| The Proterozoic Era records two periods of abundant positive carbon isotope excursions (CIEs), conventionally interpreted as resulting from increased organic carbon burial and leading to Earth’s surface oxygenation. As strong spatial variations in the amplitude and duration of these excursions are uncovered, this interpretation is challenged. Here, by studying the carbon cycle in the Dziani Dzaha Lake, we propose that they could be due to regionally variable methane emissions to the atmosphere. This lake presents carbon isotope signatures deviated by ~ + 12‰ compared to the modern ocean and shares a unique combination of analogies with putative Proterozoic lakes, interior seas or restricted epireic seas. A simple box model of its Carbon cycle demonstrates... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00656/76784/77944.pdf |
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| Brauer, Verena S.; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-guns, Veronique; Weissing, Franz J.; Stal, Lucas J.; Huisman, Jef. |
| N-2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N-2-fixing cyanobacterium Cyanothece sp. Miami BG043511 and its associated free-living chemotrophic bacteria at different concentrations of nitrate and dissolved organic carbon and different temperatures. High temperature strongly stimulated the growth of Cyanothece, but had less effect on the growth and community composition of the chemotrophic bacteria. Conversely, nitrate and carbon addition did not significantly increase the abundance of Cyanothece, but strongly affected the abundance and... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00253/36435/73426.pdf |
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| Sarazin, Gérard; Jezequel, Didier; Leboulanger, Christophe; Fouilland, Eric; Le Floc'H, Emilie; Bouvy, Marc; Gerard, Emmanuelle; Agogué, Hélène; Bernard, Cédric; Hugoni, Mylène; Grossi, Vincent; Trousselier, Marc; Ader, Magali. |
| Dziani Dzaha is a maar the age of which is close to 4000 years. While its water is thought to have originated from seawater it is now considered as an extreme environment due to its hypersaline and alkaline characteristics. Those extreme features have led to the simplification of the trophic network. Cyanobacteria account for up to 95% of the photosynthetic biomass. The main biogeochemical processes, i.e. photosynthesis, bacterial sulfate reduction and methanogenesis could explain the current water composition. As far as we know, this ecosystem could be unique on Earth, extending the nature and chemical limits of aquatic inland ecosystems |
| Tipo: Text |
Palavras-chave: Thalassohaline lake; Endorheic ecosystem; Cyanobacteria; Methane emission; Biogeochemistry; Mayotte. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00667/77948/80128.pdf |
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| Trottet, Aurore; Leboulanger, Christophe; Vidussi, Francesca; Pete, Romain; Bouvy, Marc; Fouilland, Eric. |
| The importance of heterotrophic bacteria relative to phytoplankton in the uptake of ammonium and nitrate was studied in Mediterranean coastal waters (Thau Lagoon) during autumn, when the Mediterranean Sea received the greatest allochthonous nutrient loads. Specific inhibitors and size-fractionation methods were used in combination with isotopic N-15 tracers. NO3 (-) and NH4 (+) uptake was dominated by phytoplankton (60 % on average) during the study period, which included a flood event. Despite lower biomass specific NH4 (+) and NO3 uptake rates, free-living heterotrophic bacteria contributed significantly (> 30 %) to total microbial NH4 (+) and NO3 (-) uptake rates in low chlorophyll waters. Under these conditions, heterotrophic bacteria may be... |
| Tipo: Text |
Palavras-chave: Bacteria; Phytoplankton; Inhibitors; Size fractionation; Nitrogen uptake; Dissolved inorganic nitrogen. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42497/41907.pdf |
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| Ben Othman, Hiba; Pringault, Olivier; Louati, Hela; Hlaili, Asma Sakka; Leboulanger, Christophe. |
| Effects of sediment-released contaminants and nitrogen were assessed on phytoplankton communities sampled from Thau lagoon (France, Mediterranean Sea) and one close offshore marine station. Phytoplankton was exposed to sediment elutriate (seawater containing a mix of metals, organic chemicals, and nutrients) or to ammonium enrichment for four days using immersed microcosms exposed to natural conditions of light and temperature. Functional (production - respiration balance) and structural (taxonomy and cell densities) responses of the phytoplankton community were assessed. In the lagoon, both treatments stimulated phytoplankton growth, compare to controls. Conversely in the offshore station, the phytoplankton growth was stimulated only with the sediment... |
| Tipo: Text |
Palavras-chave: Sediment resuspension; Mediterranean lagoon; Contaminants; Nutrients; Phytoplankton community. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00352/46364/46317.pdf |
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| Fouilland, Eric; Gales, Amandine; Beaugelin, Ines; Lanouguere, Elodie; Pringault, Olivier; Leboulanger, Christophe. |
| When microalgae are exposed to contaminants, the role of associated bacteria within the phycosphere, the microenvironment surrounding algal cells, remains largely unknown. The present study investigated the importance of algae-associated bacteria on the responses of microalgae growth to metallic and organic toxicant exposure. The effects of a polluted sediment elutriate, and of metal or pesticide mixtures at environmentally relevant concentrations (<10 μg L−1) were assessed on the growth of two microalgae strains: Isochrysis galbana, a prymnesiophyte, and Thalassiosira delicatula, a centric diatom. Both cultures were maintained as axenic or bacterized under similar conditions in batch cultures. In axenic conditions, the metal mixture addition at low... |
| Tipo: Text |
Palavras-chave: Microbial interactions; Metallic and pesticide contaminants; Sediments. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56422/58325.pdf |
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| Gerard, Emmanuelle; De Goeyse, Siham; Hugoni, Mylene; Agogue, Helene; Richard, Laurent; Milesi, Vincent; Guyot, Francois; Lecourt, Lena; Borensztajn, Stephan; Joseph, Marie-beatrice; Leclerc, Thomas; Sarazin, Gerard; Jezequel, Didier; Leboulanger, Christophe; Ader, Magali. |
| Lake Dziani Dzaha is a thalassohaline tropical crater lake located on the "Petite Terre" Island of Mayotte (Comoros archipelago, Western Indian Ocean). Stromatolites are actively growing in the shallow waters of the lake shores. These stromatolites are mainly composed of aragonite with lesser proportions of hydromagnesite, calcite, dolomite, and phyllosilicates. They are morphologically and texturally diverse ranging from tabular covered by a cauliflower-like crust to columnar ones with a smooth surface. High-throughput sequencing of bacterial and archaeal 16S rRNA genes combined with confocal laser scanning microscopy (CLSM) analysis revealed that the microbial composition of the mats associated with the stromatolites was clearly distinct from that of the... |
| Tipo: Text |
Palavras-chave: Stromatolites; Alkaline lake; Pleurocapsales; Mg-silicate; Alphaproteobacteria; Anoxygenic phototrophic bacteria; Aragonite; Hydromagnesite. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00443/55451/56970.pdf |
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| Leboulanger, Christophe; Agogue, Helene; Bernard, Cecile; Bouvy, Marc; Carre, Claire; Cellamare, Maria; Duval, Charlotte; Fouilland, Eric; Got, Patrice; Intertaglia, Laurent; Lavergne, Celine; Le Floc'H, Emilie; Roques, Cecile; Sarazin, Gerard. |
| This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.614.5 g L-1 eq. CO32-, i.e. 160220 mM compare to around 22.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 mu g chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00625/73731/74808.pdf |
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| Bouvy, Marc; Dupuy, Christine; Got, Patrice; Domaizon, Isabelle; Carré, Claire; Pagano, Marc; Debroas, Didier; Roques, Cécile; Leboulanger, Christophe. |
| Planktonic communities from Juan de Nova lagoon were submitted to a single exposure of diuron or naphthalene in triplicate outdoor 40-L mesocosms for 5 days. The study followed the temporal changes of the assemblages by determining abundances and taxonomic level of microbial (heterotrophic prokaryotes, picocyanobacteria, heterotrophic protists and phytoplankton) and metazooplankton communities. Exposure to both contaminants did not result in significant changes in phytoplankton abundances. Microscopic identification demonstrated the dominance of Bacillariophyta (mostly Chaetoceros tenuissimus) accounting for more than 95% of the microalgae detected in all mesocosms. Using 18S rRNA metabarcoding, temporal changes in the proportion of eukaryotic operational... |
| Tipo: Text |
Palavras-chave: Contaminant; Taxonomy; Metabarcoding; Plankton; Experiments; Lagoon.. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00681/79348/81853.pdf |
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| Hugoni, Mylene; Escalas, Arthur; Bernard, Cecile; Nicolas, Sebastien; Jezequel, Didier; Vazzoler, Fanny; Sarazin, Gerard; Leboulanger, Christophe; Bouvy, Marc; Got, Patrice; Ader, Magali; Troussellier, Marc; Agogue, Helene. |
| Thalassohaline ecosystems are hypersaline environments originating from seawater in which sodium chloride is the most abundant salt and the pH is alkaline. Studies focusing on microbial diversity in thalassohaline lakes are still scarce compared with those on athalassohaline lakes such as soda lakes that have no marine origin. In this work, we investigated multiple facets of bacterial, archaeal and eukaryotic diversity in the thalassohaline Lake Dziani Dzaha using a metabarcoding approach. We showed that bacterial and archaeal diversity were mainly affected by contrasting physicochemical conditions retrieved at different depths. While photosynthetic microorganisms were dominant in surface layers, chemotrophic phyla (Firmicutes or Bacteroidetes) and... |
| Tipo: Text |
Palavras-chave: Archaea; Bacteria; Eukaryotes; Extreme environment; Metabarcoding; Thalassohaline lake. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00464/57564/59738.pdf |
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| Registros recuperados: 12 | |
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