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Registros recuperados: 40 | |
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Medhioub, Walid; Sechet, Veronique; Truquet, Philippe; Bardouil, Michele; Amzil, Zouher; Lassus, Patrick; Soudant, Philippe. |
Growth and spirolide production of the toxic dinoflagellate Alexandrium ostenfeldii (Danish strain CCMP1773) were studied in batch culture and a photobioreactor (continuous cultures). First, batch cultures were grown in 450 mL flasks without aeration and under varying conditions of temperature (16 and 22 degrees C) and culture medium (L1, f/2 and L1 with addition of soil extract). Second, cultures were grown at 16 degrees C in 8 L aerated flat-bottomed vessels using L1 with soil extract as culture medium. Finally, continuous cultures in a photobioreactor were conducted at 18 degrees C in L1 with soil extract; pH was maintained at 8.5 and continuous stirring was applied. This study showed that A. ostenfeldii growth was significantly affected by temperature.... |
Tipo: Text |
Palavras-chave: Alexandrium ostenfeldii; Batch; Growth; Photobioreactor; Spirolide production. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16050/15784.pdf |
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Reveillon, Damien; Abadie, Eric; Sechet, Veronique; Brient, Luc; Savar, Veronique; Bardouil, Michele; Hess, Philipp; Amzil, Zouher. |
beta-N-methylamino-L-alanine (BMAA) is a neurotoxic non-protein amino acid suggested to be involved in neurodegenerative diseases. It was reported to be produced by cyanobacteria, but also found in edible aquatic organisms, thus raising concern of a widespread human exposure. However, the chemical analysis of BMAA and its isomers are controversial, mainly due to the lack of selectivity of the analytical methods. Using factorial design, we have optimized the chromatographic separation of underivatized analogues by a hydrophilic interaction chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) method. A combination of an effective solid phase extraction (SPE) clean-up, appropriate chromatographic resolution and the use of specific mass spectral... |
Tipo: Text |
Palavras-chave: Cyanotoxins; BMAA; DAB; AEG; HILIC-MS/MS; Cyanobacteria; Bivalve mollusks; French Mediterranean. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00245/35579/34112.pdf |
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Bardouil, Michele; Masselin, Pierre; Bohec, Madeleine. |
Laboratory assays have been performed, using mussels contamined with Dinophysis, in order to assess potential depurations kinetics. Mussels samples from Seine bay, Douarnenez bay and Vilaine bay have been tested . From these assays, which are to be performed in 1989; two main results are stressed : 1) when the toxicity level is near 0,5 MU/g of hepatopancreas*, depuration is undedectable during twelve days, 2) when the toxicity level exceeds 1 MU/g,depuration is important during the first eight days. *(quarantine level used by Japanese authorities) . |
Tipo: Text |
Palavras-chave: Moules; DSP; Dinophysis; Décontamination; Blue mussels; DSP; Dinophysis; Depuration. |
Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00430/54148/55479.pdf |
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Akcha, Farida; Arzul, Genevieve; Rousseau, Sabrina; Bardouil, Michele. |
The alkaline comet assay was tested on different microalgae: the clinofiagellates, Karenia mikimotoi and Alexandrium minuturn, and the diatom, Chaetoceros gracilis. The microalgae were exposed during their exponential growth to the model direct genotoxicant, hydrogen peroxide (1 h, 5 and 100 pM H2O2). Following H2O2 exposure, the comet assay was validated only for K. mikimotoi for which genotoxicity was observed from the lowest tested concentration of 5 pM with a concentration-dependent effect. C. gracilis was too small in size (4 mu m) to be correctly analysed. For A. minuturn, our lysis buffer was not strong enough to digest the cellulosic thecal plates. For K. mikimotoi, the comet assay was thus applied for the study of the genotoxic effects of... |
Tipo: Text |
Palavras-chave: Comet assay; Genotoxicity; Pesticides; Phytoplankton. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4504.pdf |
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Baron, Regis; Couedel, Marielle; Joret, Camille; Garen, Pierre; Truquet, Philippe; Masselin, Pierre; Bardouil, Michele; Lassus, Patrick. |
A simple system was used to simulate the effect of alternating toxic (paralytic shellfish poisoning toxins) and non-toxic microalgal diets on oyster feeding behaviors and rates of toxin accumulation. These experimental conditions were meant to reflect, to some extent, the incoming and outgoing fluxes of toxic algae observed at the mouth of the Penze estuary (Northern Brittany, France). Physiological and toxicological parameters were estimated based oil fluorescence measurements recorded continuously at the outlet of each experimental tank, which contained a single oyster. Q(tox), this variable describes toxin uptake in oysters, it was used (instead of the toxin ingestion rate): i) in simple graphical analyses, ii) as well as in one- and two-compartment... |
Tipo: Text |
Palavras-chave: Skeletonema costatum; Alexandrium minutum; Fluorescence; Modeling; Kinetics; Toxin uptake; Shellfish toxin; PSP. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1400.pdf |
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Lassus, Patrick; Bardouil, Michele; Masselin, Pierre; Naviner, Magali; Truquet, Philippe. |
A sea water recirculating flume was especially designed in the framework of this study. It improves physiological and ecophysiological evaluation of a 25 oysters (c. gigas) set fed on PSP toxic A. minutum cultures and then detoxified with commonly used aquaculture species (I. galbana, T. suecica, S. costatum, T. weissflogii). Chlorophyll a levels are kept steady in each case and adjusted in order to reach the same food value in each tank (0,5 mg/l TPM). When exposed to the mildly toxic species A. minutum (0,5 pg.eq.STX.cel-1) oysters depict a reduced clearance rate, food uptake and shell-valves activity (compared to non-toxic algal diets). The same physiological parameters do not show any significant differences when oysters are exposed to the control al... |
Tipo: Text |
Palavras-chave: Épuration; Crassostrea gigas; Alexandrium minutum; PSP; Écophysiologie; Depuration; C. gigas; A. minutum; PSP; Ecophysiology. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00139/25021/23126.pdf |
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Medhioub, Walid; Gueguen, Marielle; Lassus, Patrick; Bardouil, Michele; Truquet, Philippe; Sibat, Manoella; Nejib, Medhioub; Philippe, Soudant; Mejdeddine, Kraiem; Amzil, Zouher. |
In the Gulf of Gabes (Tunisia, Eastern Mediterranean sea), the grooved carpet shell Ruditapes decussatus has been seen to contain persistent levels of gymnodimine (GYM) for several years. The present experimental work represents the first attempt to assess detoxification kinetics of fast-acting toxins (FAT) in marine molluscs fed specific diets of non-toxic algae (Isochrysis galbana). To find an optimal detoxification method, two experiments were performed in which clams were first fed the toxic dinoflagellate Karenia selliformis to artificially contaminate them with GYM, thus simulating the effect of natural toxic episodes. As a second step, the same clams were fed a non-toxic algae, I. galbana. to speed up the detoxification process. Changes in toxin... |
Tipo: Text |
Palavras-chave: Ruditapes decussates; Grooved carpet shell; Karenia selliformis; Gymnodimine; Toxicity; Detoxification. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/publication-7488.pdf |
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Gueguen, Marielle; Bardouil, Michele; Baron, Regis; Lassus, Patrick; Truquet, Philippe; Massardier, Julie; Amzil, Zouher. |
Contamination of shellfish by paralytic shellfish poisoning ( PSP) toxins poses an economic threat to shellfish farmers. As contaminated shellfish cannot be harvested for long periods of time, it would be very useful to develop processes to optimise and shorten their detoxification. In this study, Pacific oysters Crassostrea gigas were first experimentally contaminated over a period of 13 days with a continuous flow of toxic Alexandrium minutum cultures at concentrations ranging from 150 to 200 cell ml(-1) ( toxin content after 13 days of contamination 438 mu g STX equiv. 100 g(-1) wet weight). Then, two different detoxification treatments were tested and showed detoxification rates greater than those observed in coastal environments. The first treatment... |
Tipo: Text |
Palavras-chave: Alexandrium minutum; Crassostrea gigas; Detoxification; Inorganic matter; Organic matter; PSP; Paralytic shellfish poisoning. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3896.pdf |
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Lassus, Patrick; Bardouil, Michele. |
A partir d'observations récentes en microscopie photonique et à balayage il est devenu nécessaire de réviser la dénomination de Dinophysis acuminata donnée à différentes espèces proches. Des échantillons phytoplanctoniques prélevés en différents points des côtes françaises ont été examinés par le Professeur BALECH en Argentine et les exemplaires de Méditerranée et des côtes sud bretonnes ont été identifiés comme D. sacculus. Compte tenu des données bibliographiques sur la répartition du genre Dinophysis sur les côtes françaises et du caractère toxique de certaines espèces, quelques recommandations sont émises concernant les dénombrements effectués dans le cadre du contrôle phytoplanctonique des eaux conchylicoles. |
Tipo: Text |
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Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00119/23001/20831.pdf |
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Wildish, David; Lassus, Patrick; Martin, Jennifer; Saulnier, Alinne; Bardouil, Michele. |
The effects of toxic and non-toxic strains of Alexandrium sp. on the initial feeding responses of the Pacific oyster Crassostrea gigas were determined by continuous monitoring of the clearance rate of individual oysters. This was determined fluorometrically by loss of fluorescence of live microalgae introduced as food. Feeding oysters with toxic or non-toxic A. tamarense and toxic A. fundyense resulted in stop/start clearance behaviour. In contrast, control oysters fed a reference microalga, Isochrysis sp., known to support their growth, did not exhibit this behavior. Pacific oysters acclimated to Isochrysis sp., fed mixtures of Alexandrium/Isochrysis, showed further evidence of stop/start clearance. Exposure for periods up to 48 hours with non-toxic A.... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Physiologie alimentaire; Microalgues toxiques; Dinoflagellés; Paralytic shellfish poisoning; Crassostrea gigas; Feeding physiology; Toxic microalgae; Dinoflagellate; Paralytic shellfish poisoning. |
Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/1998/publication-877.pdf |
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Marcaillou-le Baut, Claire; Bardin, B.; Bardouil, Michele; Bohec, Madeleine; Le Dean, Loic; Masselin, Pierre; Truquet, Philippe. |
Two studies of depuration, one in laboratory conditions and the other one in an oyster's pond were performed using 2 sets of contaminated mussels with diarrhetic toxins at a high and a low level (3 and 1 M.U.). Depuration kinetics were followed both by the adult mouse test and okadaïc acid analysis. Results are - in the pond, high toxic mussels need about 20 days to become eatable (toxicity level : 0.5 M.U.g-1 digestive glands), -this time decreases when the initial toxicity is low but it increases when mussels are underfed, - a good correlation is observed between the total toxicity and okadaïc acid concentration. |
Tipo: Text |
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Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00075/18595/16148.pdf |
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Marcaillou Le Baut, C; Bardouil, Michele; Bocquene, Gilles; Le Dean, Loic; Truquet, Philippe. |
This work is the preliminary synthesis of some toxicological tests conducted on three pesticides. This recapitulation would not have been possible without the contribution of our trainees, Misses V. Perles and H. Le Boulicot and MM. M. Falchier and G. Gaty who contributed largely to this study, supervised by the laboratory staff. The obtained results cannot be considered as definitive. The urge to answer the needs did not leave us enough time to fine tune and/or complete the results; for example we still have not determined the lethal dose for 50% of the individuals. [...] |
Tipo: Text |
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Ano: 1983 |
URL: https://archimer.ifremer.fr/doc/1983/rapport-4575.pdf |
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Bardouil, Michele; Bohec, Madeleine; Bougrier, Serge; Lassus, Patrick; Truquet, Philippe. |
An experimental flow-through system allowing determination of the feeding behaviour of individual molluscs was used to study oysters exposed to mixed diets composed of varying proportions of the diatom Thalassiosira weissflogii and two strains (toxic and nontoxic) of the dinoflagellate Alexandrium larnarense. Our results show that, when compared to a T. weissflogii unialgal diet, even a diatomltoxic dinoflagellate ratio as low in biomass as 90/10 reduced clearance rates and biodeposit production by oysters. Consumption was slightly but significantly decreased for a 50/50 diatomltoxic dinoflagellate mixture. For the toxic dinoflagellate unialgal diet, ingestion, absorption and consumption were completely inhibited. Thus, the inclusion of low amounts of... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Thalassiosira weissflogii; Alexandrium tamarense; Ecophysiologie; Toxine paralysante des coquillages; Crassostrea gigas; Thalassiosira weissflogii; Alexandrium tamarense; Ecophysiology; Paralytic shellfish poison. |
Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00017/12788/9729.pdf |
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Gueguen, Marielle; Lassus, Patrick; Laabir, Mohamed; Bardouil, Michele; Baron, Regis; Sechet, Veronique; Truquet, Philippe; Amzil, Zouher; Barille, Laurent. |
The occurrence of new phytoplankton species in a coastal area may be explained by the import of shellfish containing whole live algal cells in their digestive tracts. Indeed, shellfish containing toxic algal cells can induce both primary contaminations in safe areas ( initially free from toxic microalgae), and secondary contaminations of other shellfish growing in the same area via the faeces of the imported animals. To mitigate this problem, shellfish need to be placed in a separate holding tank and their intestinal content purged. For a deeper understanding of the risks associated with transferring contaminated shellfish, oysters ( Crassostrea gigas) and mussels ( Mytilus edulis) were purposely fed either Alexandrium minutum or A. catenella (... |
Tipo: Text |
Palavras-chave: Risk assessment; Toxic phytoplankton; Uptake; Gut passage; Mytilus edulis; Crassostrea gigas. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3897.pdf |
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Lassus, Patrick; Bardouil, Michele; Baron, Regis; Berard, Jean-baptiste; Masselin, Pierre; Truquet, Philippe; Pitrat, Jp. |
Shellfish production, and production of marine bivalve molluscs in particular, is the main form of marine aquaculture in the European Union, with a production estimated at 1,200,000 tons in 1999 (Food and Agricultural Organization). Moreover, aquaculture production is rapidly expanding throughout Europe and is becoming a major economic resource in developing areas such as Northern Greece, Ireland, and northwestern Spain. These shellfish, mainly mussels, oysters, and clams, are produced in a natural environment. Due to variations in their environment, these otherwise edible species may however become unsafe for human consumption. Potential problems are amplified due to the nature of shellfish themselves: as they are filter feeders, they consume large... |
Tipo: Text |
Palavras-chave: Detoxification; PSP toxin; Toxic algae; Bioaccumulation; Contaminant; Clam; Mussel; Oyster; Shellfish culture. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-2271.pdf |
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Proniewsk, F.; Lassus, Patrick; Bocquene, Gilles; Miossec, Laurence; Bardouil, Michele. |
Dans deux rapports précédents (LASSUS et PRONIEWSKI, 1982 - LE DEAN et Al. , 1983) un certain nombre d'éléments de réponse avaient été apportés quant aux effets d'un pH bas (2,8 à 3,0) en milieu marin, pendant une durée brève, sur la faune et la flore marines. |
Tipo: Text |
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Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/00045/15632/13035.pdf |
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Gueguen, Marielle; Baron, Regis; Bardouil, Michele; Haberkorn, Hansy; Soudant, Philippe; Truquet, Philippe; Lassus, Patrick. |
The purpose of this study was to assess paralytic phycotoxin uptake in diploid and triploid oysters at two stages of their sexual cycle corresponding to their status in early summer (June) and winter (November). Samples of diploid and triploid oysters were exposed to a toxic culture of Alexandrium minutum for 4 days in each season. No significant differences in filtration or clearance rates were observed during either November or June experiments. When diploid oysters were at resting stage (November), toxin uptake showed no significant difference between the ploidy classes. In contrast, when the diploid oysters were at the peak of their sexual maturation (June), the triploid oysters were seen to accumulate almost double the amount of paralytic toxins as... |
Tipo: Text |
Palavras-chave: Paralytic shellfish poisoning; Crassostrea gigas; Diploid; Triploid; Contamination. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19796/17487.pdf |
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Registros recuperados: 40 | |
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