Consulta: subjectFacets:"DOM"
Registros recuperados: 7
Data/hora: 03/06/2024 01:17:21

Viral degradation of marine bacterial exopolysaccharides
Provedor de dados: 5
Autores: Lelchat, Florian; Mocaer, P Y; Ojima, T; Michel, G; Sarthou, Geraldine; Bucciarelli, Eva; Cérantola, S; Colliec-jouault, Sylvia; Boisset, Claire; Baudoux, A-c.
The identification of the mechanisms by which marine dissolved organic matter (DOM) is produced and regenerated is critical to develop robust prediction of ocean carbon cycling. Polysaccharides represent one of the main constituents of marine DOM and their degradation is mainly attributed to polysaccharidases derived from bacteria. Here, we report that marine viruses can depolymerize the exopolysaccharides (EPS) excreted by their hosts using 5 bacteriophages that infect the notable EPS producer, Cobetia marina DSMZ 4741. Degradation monitorings as assessed by gel electrophoresis and size exclusion chromatography showed that 4 out of 5 phages carry structural enzymes that depolymerize purified solution of Cobetia marina EPS. The depolymerization patterns...
Tipo: Text
Palavras-chave: Marine phage; EPS; Polysaccharidase; DOM; Ocean.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00499/61062/64512.pdf

Influence de la matière organique dissoute naturelle et d’herbicides, seuls et combinés, sur des microalgues marines et d’eau douce
Provedor de dados: 5
Autores: Coquillé, Nathalie.
Microalgae are at the basis of aquatic food webs and may be the indirect target of herbicides from agricultural and urban uses. They also interact with other compounds from their environment such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This thesis aimed to study, in laboratory controlled conditions, the influence of natural DOM on herbicide toxicity to microalgae by using monospecific, non-axenic cultures. The experiments included: natural freshwater and marine DOM, three herbicides (irgarol, diuron and S-metolachlor) singly and in mixtures, two freshwater microalgae (Gomphonema gracile and Sphaerellopsis sp.) and two marine microalgae (Chaetoceros calcitrans and Tetraselmis suecica). Effects were evaluated on...
Tipo: Text
Palavras-chave: Microalgues; Matière organique dissoute naturelle; MOD; Herbicides; Transformations chimiques; Toxicité.; Microalgae; Natural dissolved organic matter; DOM; Herbicides; Chemical transformations; Toxicity.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00461/57245/59250.pdf

Rapport sur l'exercice de la pêche dans la zone côtière de la France
Provedor de dados: 5
Autores: Bolopion, Jacques; Forest, Andre; Sourd, Louis-julien.
The maritime fisheries and mariculture guidance law passed in 1997 specifies that with the perspective of renegotiation of the common fisheries policy in 2002, a report on the special conditions of inshore fisheries be drawn up by the Government. To do so, the Minister of Agriculture and Fisheries entrusted this task to three experts, who are the authors of this report. In accordance with their remit, the situation of fisheries in territorial waters and estuaries of metropolitan France and the four DOM overseas departments ( counties) was examined, in the framework of meetings with professional fishermen, administrations, elected officials and scientific organisations. The first part situates fishing activities in coastal areas within the overall context...
Tipo: Text
Palavras-chave: Gestion; Manche; Méditerranée; Gascogne; DOM; Conflits d'usages; Pêche côtière; Management; Channel; Mediterranean; Biscay; DOM; Conflicting uses; Coastal fisheries.
Ano: 2000
URL: https://archimer.ifremer.fr/doc/2000/rapport-1200.pdf

The influence of natural dissolved organic matter on herbicide toxicity to marine microalgae is species-dependent
Provedor de dados: 5
Autores: Coquille, Nathalie; Menard, Dominique; Rouxel, Julien; Dupraz, Valentin; Eon, Melissa; Pardon, Patrick; Budzinski, Helene; Morin, Soizic; Parlanti, Edith; Stachowski-haberkorn, Sabine.
Microalgae, which are the foundation of aquatic food webs, may be the indirect target of herbicides used for agricultural and urban applications. Microalgae also interact with other compounds from their environment, such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This study aimed to evaluate the influence of natural DOM on the toxicity of three herbicides (diuron, irgarol and S-metolachlor), singly and in ternary mixtures, to two marine microalgae, Chaetoceros calcitrans and Tetraselmis suecica, in monospecific, non-axenic cultures. Effects on growth, photosynthetic efficiency (Ф’M) and relative lipid content were evaluated. The chemical environment (herbicide and nutrient concentrations, dissolved organic carbon...
Tipo: Text
Palavras-chave: Microalgae; Herbicides; Natural dissolved organic matter; DOM; Toxicity; Interactions.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00428/53964/55113.pdf

Etude sur les contaminants émergents dans les eaux françaises - Rapport de l'étude prospective sur les contaminants émergents dans les eaux littorales de la métropole et des DOM
Provedor de dados: 5
Autores: Abarnou, Alain; Bocquene, Gilles; Champin, Maryline; Durand, Gaetane; Gonzalez, Jean-louis; Le Moigne, Morgan; Masson, Jean-claude; Priou, Pierre; Tixier, Celine.
This study contributes to inventory programme on emerging pollutants in French waters and to the general reflection which will enable to update the list of relevant substnaces to be included in the new monitoring programmes to come. This work concerns the coastal part of the inventory programme on marine waters and sediments of France and five overseas french departments (OFD). In this goal, passive sampling techniques and direct extraction techniques have been tested through the implementation of in situ systems integrators POCIS (Polar Organic Chemical Integrative Sampler) and the extraction by SBSE bars (Stir bar sorptive extraction) directly in the waters sampled. Finally, analyzes of sediment completed the acquisition of data. Arount 40 stations were...
Tipo: Text
Palavras-chave: Eaux littorales; Eaux côtières; Sédiment; Métropole; DOM; Pollution; Substances chimiques; POCIS; SBSE; Coastal waters; Sediment; France; Overseas french departments; Pollution; Chemicals contaminants; POCIS; SBSE.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00259/36994/35483.pdf

Interactions between a marine dinoflagellate (Alexandrium catenella) and a bacterial community utilizing reverine humic substances
Provedor de dados: 5
Autores: Carlsoon, Per; Edling, Hélène; Bechemin, Christian.
Dissolved organic matter in the form of riverine humic substances stimulated the growth of both axenic nitrogen-limited Alexandrium catenella cultures and nitrogen-limited cultures with a marine bacterial community present. The biomass increase of A. catenella could not be accounted for by utilization of inorganic nitrogen compounds. However, there was a considerable release of dissolved free and combined amino acids from the humic substances that was utilized by A. catenella. About 40% of the nitrogen used by A. catenella in the axenic treatment with humic substances added was taken up as organic nitrogen. Bacterial aminopeptidase and beta -glucosidase activity was stimulated by the addition of humic substances and bacterial growth increased several-fold....
Tipo: Text
Palavras-chave: Alexandrium catenella; Dinoflagellates; Bacteria; DOM; Humic substances.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/00173/28431/26763.pdf

Release of available nitrogen from river-discharged dissolved organic matter by heterotrophic bacteria associated with the cyanobacterium     Microcystis aeruginosa
Provedor de dados: 5
Autores: Purvina, S; Béchemin, Christian; Balode, M; Verite, Celine; Arnaud, Christophe; Maestrini, Serge Y.
The use of riverine dissolved organic matter by the heterotrophic bacteria associated with a culture of the cyanobacterium Microcystis aeruginosa and release of simple nitrogen compounds were studied in an experimental series. Bacteria reduced the bulk of dissolved organic nitrogen (DON) by half, but when associated with M. aeruginosa, DON was excreted and its concentration rose by 13%. During the stationary growth phase bacteria released ammonium, doubling the concentration of ammonia as well as of nitrates. Bacteria associated with M. aeruginosa consumed riverine DON and joined the ammonification and nitrification process, supplying cyanobacteria with simple nitrogen compounds.
Tipo: Text
Palavras-chave: Microcystis aeruginosa; Heterotrophic bacteria; DOM; DON; Nitrates; Ammonia.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00353/46408/46122.pdf