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| Registros recuperados: 13 | |
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| Ayache, Nour; Hervé, Fabienne; Lundholm, Nina; Amzil, Zouher; Caruana, Amandine. |
| oxic Pseudo‐nitzschia australis strains isolated from French coastal waters were studied to investigate their capacity to adapt to different salinities. Their acclimation to different salinity conditions (10, 20, 30, 35 and 40) was studied on growth, photosynthetic capacity, cell biovolume and domoic acid (DA) content. The strains showed ability to acclimate to a salinity range from 20 to 40, with optimal growth rates between salinities 30 and 40. The highest cell biovolume was observed at the lowest salinity 20 and was associated with the lowest growth rate. Salinity did not affect the photosynthetic activity; Fv/Fm values and the pigment contents remained high with no significant difference among salinities. An enhanced production of zeaxanthin was,... |
| Tipo: Text |
Palavras-chave: Acclimation; Climate change; Domoic acid; Pseudo-nitzschia australis; Physiology; Salinity. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00585/69684/67552.pdf |
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| Sauvey, Aurore; Claquin, Pascal; Le Roy, Bertrand; Le Gac, Mickael; Fauchot, Juliette. |
| We used a multi‐strain approach to study the intra‐ and interspecific variability of the growth rates of three Pseudo‐nitzschia species – P. australis, P. fraudulenta, and P. pungens – and of their domoic acid (DA) production. We carried out mating and batch experiments to investigate the respective effects of strain age and cell size, and thus the influence of their life cycle on the physiology of these species. The cell size ‐ life cycle relationship was characteristic of each species. The influence of age and cell size on the intraspecific variability of growth rates suggests that these characteristics should be considered cautiously for the strains used in physiological studies on Pseudo‐nitzschia species. The results from all three species do not... |
| Tipo: Text |
Palavras-chave: Cell size; Domoic acid; Growth; Life cycle; Pseudo-nitzschia strains. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61679/65622.pdf |
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| Caruana, Amandine; Ayache, Nour; Raimbault, Virginie; Rétho, Michael; Hervé, Fabienne; Bilien, Gwenael; Amzil, Zouher; Chomérat, Nicolas. |
| We confirm an amnesic shellfish poisoning risk associated with domoic acid production by the species Pseudo-nitzschia plurisecta and determine the toxin profile, which includes three domoic acid isomers. Although the species was reported once in European waters, along the Spanish Atlantic coast, here we describe and characterize P. plurisecta collected during the first occurrence in French Atlantic waters. Three strains (IFR-PPL-15.1, 15.2 and 15.3) were isolated from French coastal water samples in June 2015. These strains were identified and characterized by microscopic observation, molecular (ITS region sequencing and phylogenetic analysis) and metabolite (toxins and pigments) analyses. The cell shape is lanceolate and the valve contains a central... |
| Tipo: Text |
Palavras-chave: Coastal monitoring; Domoic acid; Pigment composition; Pseudo-nitzschia plurisecta; Taxonomic identification; Toxic diatoms. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61687/66033.pdf |
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| Martin-jezequel, Veronique; Calu, Guillaume; Candela, Leo; Amzil, Zouher; Jauffrais, Thierry; Sechet, Veronique; Weigel, Pierre. |
| Over the last century, human activities have altered the global nitrogen cycle, and anthropogenic inputs of both inorganic and organic nitrogen species have increased around the world, causing significant changes to the functioning of aquatic ecosystems. The increasing frequency of Pseudo-nitzschia spp. in estuarine and coastal waters reinforces the need to understand better the environmental control of its growth and domoic acid (DA) production. Here, we document Pseudo-nitzschia spp. growth and toxicity on a large set of inorganic and organic nitrogen (nitrate, ammonium, urea, glutamate, glutamine, arginine and taurine). Our study focused on two species isolated from European coastal waters: P. multiseries CCL70 and P. australis PNC1. The nitrogen... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia; Toxic diatoms; Nitrogen; Amino acids; Domoic acid. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00308/41912/41188.pdf |
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| Ruiz, Nicolas; Petit, Karina; Vansteelandt, Marieke; Kerzaon, Isabelle; Baudet, Joseph; Amzil, Zouher; Biard, Jean-francois; Grovel, Olivier; Pouchus, Yves Francois. |
| Peptaibols are small linear fungal peptides which are produced in the marine environment. They exhibit neurotoxicity by forming pores in neuronal membranes. This work describes their combine effect with domoic acid, a neurotoxic phycotoxin, on Diptera larvae. The Acute toxicity bioassay on this biological model was tested with a panel of different toxins (microbial, algal or fungal). It allowed the discrimination of neurotoxins and non-neurotoxic toxins, and an evaluation of the toxicity level (MED and ED50) which were correlated with published LD50 in mice for neurotoxins tested. The highest activities on this test were found for Na+ channel blockers tetrodotoxin (ED50 = 0.026 mg/kg) and saxitoxin (ED50 = 0.18 mg/kg). Domoic acid was less active with an... |
| Tipo: Text |
Palavras-chave: Domoic acid; Peptaibol; Synergism; Neurotoxicity; Marine-derived fungal metabolite; Diptera larvae bioassay. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11279/7886.pdf |
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| Ajani, Penelope A.; Lim, Hong Chang; Verma, Arjun; Lassudrie, Malwenn; Mcbean, Katie; Doblin, Martina A.; Murray, Shauna A.. |
| Certain species of the marine diatom genus Pseudo‐nitzschia are responsible for the production of the domoic acid (DA), a neurotoxin that can bioaccumulate in the food chain and cause amnesic shellfish poisoning (ASP) in animals and humans. This study extends our knowledge by reporting on the first observation of the potentially toxic species Pseudo‐nitzschia simulans from this region. One clonal strain of P. simulans was isolated from the East Australian Current and characterized using light and transmission electron microscopy, and phylogenetic analyses based on regions of the internal transcribed spacer (ITS) and the D1–D3 region of the large subunit (LSU) of the nuclear‐encoded ribosomal deoxyribonucleic acid (rDNA), as well as examined for DA... |
| Tipo: Text |
Palavras-chave: Domoic acid; East Australian current; Harmful algal blooms; Phytoplankton; Shellfish. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/73047/75313.pdf |
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| Amzil, Zouher; Royer, Florence; Sibat, Manoella; Fiant, Liliane; Gelin, Muriel; Le Gal, Dominique; Francoise, Sylvaine. |
| In the context of the French phytoplankton and phycotoxins monitoring network (REPHY), shellfish scallops were harvested systematically during the authorised fishing season for the purpose of investigating paralytic toxins (PSP-mouse test), amnesic toxins (ASPchemical analysis), and lipophilic toxins (DSP-mouse test). For all shellfish samples that tested positive in the DSP mouse bioassay used for lipophilic toxins detection, liquid chromatography coupled with mass spectrometry (LC-MS/MS) was used to search for the following lipophilic toxins: okadaic acid, dinophysistoxins, pectenotoxins, azaspiracids, yessotoxins, spirolides, and gymnodimine. In order to investigate the presence of okadaic acid esters (DTX3), alkaline hydrolysis was performed on all... |
| Tipo: Text |
Palavras-chave: Scallops; Domoic acid; Okadaic acid and derivatives; Dinophysis. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00015/12577/9447.pdf |
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| Ayache, Nour; Hervé, Fabienne; Martin-jézéquel, Veronique; Amzil, Zouher; Caruana, Amandine. |
| Several coastal countries including France have experienced serious and increasing problems related to Pseudo‐nitzschia toxic blooms. These toxic blooms occur in estuarine and coastal waters potentially subject to fluctuations in salinity. In this study, we document for the first time the viability, growth, photosynthetic efficiency and toxin production of two strains of Pseudo‐nitzschia australis grown under conditions with sudden salinity changes. Following salinity variation, the two strains survived over a restricted salinity range of 30 to 35, with favorable physiological responses, as the growth, effective quantum yield and toxin content were high compared to the other conditions. In addition, high cellular quotas of domoic acid (DA) were observed at... |
| Tipo: Text |
Palavras-chave: Amnesic shellfish poisoning; Domoic acid; Harmful algae; Pseudo-nitzschia australis; Salinity stress. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00462/57385/59465.pdf |
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| Lema, Anais Kimberley; Latimier, Marie; Nezan, Elisabeth; Fauchot, Juliette; Le Gac, Mickael. |
| The factors responsible for inducing the synthesis of toxins and responses from toxic phytoplankton blooms remain unclear. In this study we compare the influence of genotypic (at both the intra and interspecific levels) and environmental factors (nutrient concentration and ratio) on growth (in terms of cell densities) and domoic acid (DA) production in three Pseudo-nitzschia species: P. australis, P.pungens and P.fradulenta. A strong phosphate effect was detected. More precisely, a low initial concentration in phosphate, even at high initial nitrogen and silicate concentrations, induced the highest DA concentrations and the lowest cell densities in all strains/species studied. In contrast, a low initial concentration of nitrogen and silicate combined, with... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia strains; Domoic acid; Ratio; Phosphate; Nitrogen. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00377/48849/49397.pdf |
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| Husson, Berengere; Hernandez Farinas, Tania; Le Gendre, Romain; Schapira, Mathilde; Chapelle, Annie. |
| King scallop contamination (Pecten maximus) by domoic acid, a neurotoxin produced by some species of the diatom Pseudo-nitzschia, is highly problematic because of its lengthy retention in the bivalve tissue, leading to prolonged fishery closures. Data collected within the French Phytoplankton and Phycotoxin monitoring network (REPHY) over the 1995–2012 period were used to characterize the seasonal dynamics and the interannual variability of P.-nitzschia spp. blooms as well as the contamination of king scallop fishing grounds, in six contrasted bays distributed along the French Atlantic coast and English Channel. Monitoring revealed that these toxic events have become more frequent since the year 2000, but with varying magnitudes, frequencies and timing... |
| Tipo: Text |
Palavras-chave: Pseudo-nitzschia spp.; Domoic acid; King scallop; Interannual variability; Seasonal dynamics; Environmental parameters. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00299/40983/40084.pdf |
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| Рябушко, Л. И.; Бесиктепе, С.; Едигер, Д.; Илмаз, Д.; Зенгинер, A.; Рябушко, В. И.; Ли, Р. И.. |
| В Чёрном море в прибрежных водах Крыма впервые обнаружена диатомовая водоросль Pseudo-nitzschia calliantha Lundholm, Moestrup et Hasle, продуцирующая домоевую кислоту. Концентрация токсина в клетках водоросли, культивируемой в питательных средах F/2 и Гольдберга, составляет в среднем соответственно 0.43 и 0.145 пг·кл.-1. Рассмотрены морфология, систематика, экология и токсикологические аспекты вида. |
| Tipo: Journal Contribution |
Palavras-chave: Диатомовая водоросль; Pseudo-nitzschia; Морфология; Токсин; Домоевая кислота; Крым; Чёрное море; Diatom; Morphology; Toxin; Domoic acid; Crimea; Black Sea; Діатомова водорість; Морфологія; Домоєва кислота; Крим; Чорне море. |
| Ano: 2008 |
URL: http://repository.ibss.org.ua/dspace/handle/99011/821 |
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| Registros recuperados: 13 | |
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