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Gaillard, Sylvain; Charrier, Aurelie; Malo, Florent; Carpentier, Liliane; Bougaran, Gael; Hégaret, Helene; Réveillon, Damien; Hess, Philipp; Séchet, Veronique. |
The cryptophyte Teleaulax amphioxeia is a source of plastids for the ciliate Mesodinium rubrum and both organisms are members of the trophic chain of several species of Dinophysis. It is important to better understand the ecology of organisms at the first trophic levels before assessing the impact of principal factors of global change on Dinophysis spp. Therefore, combined effects of temperature, irradiance and pH on growth rate, photosynthetic activity and pigment content of a temperate strain of T. amphioxeia were studied using a full factorial design (central composite design 23*) in 17 individually controlled bioreactors. The derived model predicted an optimal growth rate of T. amphioxeia at a light intensity of 400 µmol photons · m‐2 · s‐1, more... |
Tipo: Text |
Palavras-chave: Dinophysis; Ecophysiology; Full factorial design; Global change; Mesodinium rubrum; Teleaulax amphioxeia. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72155/70910.pdf |
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Réveillon, Damien; Tunin-ley, Alina; Grondin, Isabelle; Othmani, Ahlem; Zubia, Mayalen; Bunet, Robert; Turquet, Jean; Culioli, Gérald; Briand, Jean-françois. |
Marine microalgae and cyanobacteria have largely been studied for their biotechnological potential and proved their ability to produce a wide array of bioactive molecules. We investigated the antifouling potential of unexplored benthic tropical microalgae using anti-adhesion and toxicity bioassays against two major micro- and ma crobiofoulers, namely bacteria and barnacles. Fifty strains belonging to six phyla [Cyanobacteria, Miozoa (Dinoflagellata), Bacillariophyta, Cryptophyta, Rhodophyta and Haptophyta] were isolated from southwestern Islands of the Indian Ocean. They were chosen in order to represent as much as possible the huge biodiversity of such a rich tropical ecosystem. The associated chemodiversity was highlighted by both NMR- and LC-MS-based... |
Tipo: Text |
Palavras-chave: Microalgae; Antifouling; Bioassay; Chemodiversity; Bioprospecting; Metabolomics. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00454/56608/58333.pdf |
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Chomérat, Nicolas; Bilien, Gwenael; Derrien, Amelie; Henry, Kévin; Ung, André; Viallon, Jérôme; Darius, Hélène Taiana; Mahana Iti Gatti, Clémence; Roué, Mélanie; Hervé, Fabienne; Réveillon, Damien; Amzil, Zouher; Chinain, Mireille. |
To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French... |
Tipo: Text |
Palavras-chave: ITS-5.8S rDNA; LSU rDNA; Microscopy; Ostreopsis lenticularis; Taxonomy; Toxins. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59747/62887.pdf |
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Georges Des Aulnois, Maxime; Roux, Pauline; Caruana, Amandine; Réveillon, Damien; Briand, Enora; Hervé, Fabienne; Savar, Veronique; Bormans, Myriam; Amzil, Zouher; Atomi, Haruyuki. |
Proliferation of microcystin (MC)-producing Microcystis aeruginosa in brackish waters has been described in several locations and represents a new concern for public and environmental health. While the impact of a sudden salinity increase on M. aeruginosa physiology has been studied, less is known about the mechanisms involved in salt tolerance after acclimation. This study aims to compare the physiological responses of two strains of M. aeruginosa (PCC 7820 and PCC 7806), which were isolated from contrasted environments, to increasing salinities. After acclimation, growth and MC production rates were determined and metabolomic analyses were conducted. For both strains, salinity decreased the biovolume, growth, and MC production rates and induced the... |
Tipo: Text |
Palavras-chave: Acclimation; Metabolomic; Microcystis; Salinity; Sucrose; Trehalose; Ecophysiology. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70031/68012.pdf |
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Georges Des Aulnois, Maxime; Réveillon, Damien; Robert, Elise; Caruana, Amandine; Briand, Enora; Guljamow, Arthur; Dittmann, Elke; Amzil, Zouher; Bormans, Myriam. |
The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the e ect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by di erences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the... |
Tipo: Text |
Palavras-chave: Microcystis aeruginosa; Microcystin; Salt stress; Metabolomic; Transcript. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72689/71692.pdf |
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Gémin, Marin-pierre; Réveillon, Damien; Hervé, Fabienne; Pavaux, Anne-sophie; Tharaud, Maxime; Séchet, Veronique; Bertrand, Samuel; Lemée, Rodolphe; Amzil, Zouher. |
Over the last fifteen years, blooms of the genus Ostreopsis have been reported more frequently and at higher abundances in the Mediterranean area. Ostreopsis cf. ovata is known to produce ovatoxins (OVTXs), structural analogues of palytoxin, which is one of the most potent non-polymeric toxins. However, the production of OVTXs is poorly characterized in situ. The present study focuses on toxin content and profile according to the bloom phase during summer 2017 in Villefranche-sur-Mer, France (NW Mediterranean Sea), depth (from 0.5 to 5 m) and three different macroalgal substrates of this epiphytic dinoflagellate (Padina pavonica, Dictyota spp. and Halopteris scoparia). Ovatoxin quantification of all samples was performed by liquid chromatography coupled to... |
Tipo: Text |
Palavras-chave: Dinoflagellate; Benthic HABs; Ostreopsis cf. ovata; Ovatoxins; Mediterranean Sea. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72566/74835.pdf |
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