Consulta: creatorFacets:"Rovillon, Georges-augustin"
Registros recuperados: 6
Data/hora: 05/06/2024 08:22:58

Lipophilic Toxin Profile in Mytilus galloprovincialis from the North Atlantic Coast of Morocco: LC-MS/MS and Mouse Bioassay Analyses
Provedor de dados: 5
Autores: Ben Haddouch, Asia; Amanhi, Rachid; Amzil, Zouher; Taleb, Hamib; Rovillon, Georges-augustin; Adly, Farida; Loutfi, Mohammed.
Forthe Moroccan Phycotoxins Monitoring that is part of theSafety of theCoastal Monitoring Network(RSSL),shellfish sampleswereharvestedfromdifferentlocations at NorthAtlantic of Morocco whereharmful algaeblooms were known to have occurred. Forallshellfishsamples found positive by themouse bioassay fordiarrheicshellfishpoisoning(DSP)toxins,liquid chromatography coupled to tandem massspectrometry(LC-MS-MS) in order to search thefollowinglipophilictoxins: okadaic acid (OA), dinophysistoxins(DTXs), pectenotoxins(PTXs), azaspiracids(AZAs), yessotoxins(YTXs), spirolides(SPXs) and gymnodimines (GYMs).Theresultsrevealeddifferentlipophilictoxinprofiles as a function of theshellfish sampling location. It has beennoticed that allthesamples contained OA and its...
Tipo: Text
Palavras-chave: Diarrheictoxins; Lipophilic toxins; LC-MS/MS; Mouse test; Shellfish.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00372/48342/48495.pdf

From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains?
Provedor de dados: 5
Autores: Geffroy, Solene; Lechat, Marc-marie; Le Gac, Mickael; Rovillon, Georges-augustin; Marie, Dominique; Bigeard, Estelle; Malo, Florent; Amzil, Zouher; Guillou, Laure; Caruana, Amandine.
Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes...
Tipo: Text
Palavras-chave: Alexandrium; Saxitoxins; SxtA4; Copy number variation; SxtA; Expression; Isoform.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00682/79402/81944.pdf

Effects of copper and butyltin compounds on the growth, photosynthetic activity and toxin production of two HAB dinoflagellates : the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata
Provedor de dados: 5
Autores: Couet, Douglas; Pringault, Olivier; Bancon-montigny, Chrystelle; Briant, Nicolas; Poulichet, Francoise Elbaz; Delpoux, Sophie; Yahia, Ons Kefi-daly; Hela, Bengharbia; Charaf, M'Rabet; Herve, Fabienne; Rovillon, Georges-augustin; Amzil, Zouher; Laabir, Mohamed.
Controlled laboratory experiments were conducted to test the effects of copper (Cu2+) and butyltins (BuT) on the growth, photosynthetic activity and toxin content of two HABs (Harmful Algal Blooms) dinoflagellates, the planktonic Alexandrium catenella and the benthic Ostreopsis cf. ovata. Microalgae were exposed to increasing concentrations of Cu2+ (10−4 to 31 nM) or BuT (0.084 to 84 nM) for seven days. When considering the growth, EC50 values were 0.16 (±0.09) nM and 0.03 (±0.02) nM of Cu2+ for A. catenella and O. cf. ovata, respectively. Regarding BuT, EC50 was 14.2 (±6) nM for O. cf. ovata, while A. catenella growth inhibition appeared at BuT concentrations ≥27 nM. Photosynthetic activity of the studied dinoflagellates decreased with increasing Cu and...
Tipo: Text
Palavras-chave: Alexandrium catenella; Ostreopsis cf. ovata; Cu; Butyltin; Photosynthesis; Toxins.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00418/52970/53896.pdf

New insights on the species-specific allelopathic interactions between macrophytes and marine HAB dinoflagellates
Provedor de dados: 5
Autores: Ben Gharbia, Hela; Yahia, Ons Kefi-daly; Cecchi, Philippe; Masseret, Estelle; Amzil, Zouher; Herve, Fabienne; Rovillon, Georges-augustin; Nouri, Habiba; M'Rabet, Charaf; Couet, Douglas; Triki, Habiba Zmerli; Laabir, Mohamed.
Macrophytes are known to release allelochemicals that have the ability to inhibit the proliferation of their competitors. Here, we investigated the effects of the fresh leaves of two magnoliophytes (Zostera noltei and Cymodocea nodosa) and thalli of the macroalgae Ulva rigida on three HAB-forming benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis). The effects of C. nodosa and U. rigida were also tested against the neurotoxic planktonic dinoflagellate Alexandrium pacificum Litaker sp. nov (former Alexandrium catenella). Co-culture experiments were conducted under controlled laboratory conditions and potential allelopathic effects of the macrophytes on the growth, photosynthesis and toxin production of the targeted...
Tipo: Text
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00411/52200/52917.pdf

Bassins insubmersibles et contamination par les micro-algues toxiques (BICMAT)
Provedor de dados: 5
Autores: Derrien, Amelie; Terre Terrillon, Aouregan; Duval, Audrey; Lebrun, Luc; Doner, Anne; Rovillon, Georges-augustin; Amzil, Zouher; Le Bec, Claude.
En cas de fermeture de zone de production pour cause de présence d'une espèce de micro algues toxique, une mesure prévoit pour les professionnels de la conchyliculture l'interdiction générale d'utilisation de l'eau de mer déjà pompée dans un bassin insubmersible. C'est dans ce contexte que la DGAL a sollicité l'appui du LER BO pour la mise en place d'une étude dans des conditions professionnelles. Cette étude vise à déterminer d'il existe un risque de contamination lors de l'immersion de coquillages non contaminés dans un bassun insubmersible rempli en eau de mer pompée dans une zone fermée pour cause de présence de micro-algues toxiques. Entre fin juin et début juillet, la présence de Dinophysis sp a entraîné la fermeture de la baie de Concarneau. Des...
Tipo: Text
Palavras-chave: Dinophysis; Toxines lipophiles; Acide okadaïque; Yessotoxines; Bassin insubmersible; Huîtres; Moules.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59736/62831.pdf

Characterization of toxin-producing strains of Dinophysis spp. (Dinophyceae) isolated from French coastal waters, with a particular focus on the D. acuminata-complex
Provedor de dados: 5
Autores: Séchet, Veronique; Sibat, Manoella; Bilien, Gwenael; Carpentier, Liliane; Rovillon, Georges-augustin; Raimbault, Virginie; Malo, Florent; Gaillard, Sylvain; Perrière-rumebe, Myriam; Hess, Philipp; Chomérat, Nicolas.
Dinoflagellates of the genus Dinophysis are the most prominent producers of Diarrhetic Shellfish Poisoning (DSP) toxins which have an impact on public health and on marine aquaculture worldwide. In particular, Dinophysis acuminata has been reported as the major DSP agent in Western Europe. Still, its contribution to DSP events in the regions of the English Channel and the Atlantic coast of France, and the role of the others species of the Dinophysis community in these areas are not as clear. In addition, species identification within the D. acuminata complex has proven difficult due to their highly similar morphological features. In the present study, 30 clonal strains of the dominant Dinophysis species have been isolated from French coasts including the...
Tipo: Text
Palavras-chave: Dinophysis spp; . Phylogeny; Taxonomy; Toxin profiles.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00679/79081/81880.pdf