Consulta: creatorFacets:"Berard, Jean-baptiste"
Registros recuperados: 17
Data/hora: 17/06/2024 10:54:19

Modélisation de la contamination des bivalves par les toxines d'Alexandrium spp. Rapport final
Provedor de dados: 5
Autores: Lassus, Patrick; Amzil, Zouher; Bardouil, Michele; Baron, Regis; Bohec, Madeleine; Bougrier, Serge; Garen, Pierre; Laabir, Mohamed; Leguay, Didier; Masselin, Pierre; Truquet, Philippe; Sechet, Veronique; Bablon, Clotilde; Berard, Jean-baptiste; Carre, Camille; Cheignon, Valerie; Lecamp, Sylvain; Mabit, Marie.
L'objectif général de l'étude est de simuler les épisodes de contamination de certains bivalves (huîtres et moules) par les toxines d'Alexandrium minutum et A. calenella à partir d'un module expérimental adapté, et en vue de construire un modèle de contamination applicable à ces espèces. Ce modèle sera ensuite susceptible d'être couplé aux modèles biologiques locaux (estuaire de Penzé et étang de Thau) de déterminisme des blooms, ainsi qu'aux modèles hydrodynamiques développés par différentes équipes (Ifremer, Université de Montpellier). La première année (2001-2002) était consacrée à la simulation des contaminations en estuaire de Penzé (Alexandrium minulum) et au développement de cultures en masse d'A. calenella de Thau en bioréacteurs.
Tipo: Text
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00156/26711/24786.pdf

Screening and selection of growth-promoting bacteria for Dunaliella cultures
Provedor de dados: 5
Autores: Le Chevanton, Myriam; Garnier, Matthieu; Bougaran, Gael; Schreiber, Nathalie; Lukomska, Ewa; Berard, Jean-baptiste; Fouilland, E.; Bernard, Olivier; Cadoret, Jean-paul.
Previous studies have demonstrated that bacteria influence microalgal metabolism, suggesting that the selection and characterization of growth-promoting bacteria should offer a new strategy for improving industrial algal cultivation. In the present study, 48 cultivable bacteria were isolated from marine microalgae species and identified using 16S rRNA phylogenetic analysis. The recovered bacteria were found to be members of the α- and γ-Proteobacteria, Cytophaga–Flavobacterium–Bacteroides (CFB) and gram-positive monophyletic clusters. To address the effect of these bacteria on the growth of Dunaliella sp. individually, an experimental high-throughput tool was developed to simultaneously compare replicated associations. A two-step approach was used to...
Tipo: Text
Palavras-chave: Microalgae; Dunaliella; Bacteria; Interaction; Bacterial diversity.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00142/25334/24768.pdf

Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups
Provedor de dados: 5
Autores: Serive, Benoit; Nicolau, Elodie; Berard, Jean-baptiste; Kaas, Raymond; Pasquet, Virginie; Picot, Laurent; Cadoret, Jean-paul.
Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature. Using an optimized extraction process coupled to a HPLC de-replication strategy, we examined the pigment composition of 37...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00373/48416/48627.pdf

Improving detoxification Efficiency of PSP-contaminated oysters (Crassostrea gigas Thunberg)
Provedor de dados: 5
Autores: 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

Toxic dinoflagellates (Alexandrium fundyense and A-catenella) have minimal apparent effects on oyster hemocytes
Provedor de dados: 5
Autores: Hegaret, Hélène; Wikfors, Gary H.; Soudant, Philippe; Lambert, Christian; Shumway, Sandra E.; Berard, Jean-baptiste; Lassus, Patrick.
The possible effect of Alexandrium spp. containing paralytic shellfish poisoning (PSP) toxins on the hemocytes of oysters was tested experimentally. In one trial, eastern oysters, Crassostrea virginica Gmelin, were exposed to bloom concentrations of the sympatric dinoflagellate, Alexandrium fundyense Balech, alone and in a mixture with a non-toxic diatom, Thalassiosira weissflogii (Grun) Fryxell et Hasle. Subsequently, another experiment exposed Pacific oysters, Crassostrea gigas Thunberg, to a mixed suspension of the sympatric, toxic species Alexandrium catenella (Whedon et Kofoid) Balech, with T. weissflogii. Measurements of numbers of oyster hemocytes, percentages of different cell types, and functions (phagocytosis, reactive oxygen species (ROS)...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3328.pdf

Production and Isolation of Azaspiracid-1 and -2 from Azadinium spinosum Culture in Pilot Scale Photobioreactors
Provedor de dados: 5
Autores: Jauffrais, Thierry; Kilcoyne, Jane; Sechet, Veronique; Herrenknecht, Christine; Truquet, Philippe; Herve, Fabienne; Berard, Jean-baptiste; Nulty, Ciara; Taylor, Sarah; Tillmann, Urban; Miles, Christopher O.; Hess, Philipp.
Azaspiracid (AZA) poisoning has been reported following consumption of contaminated shellfish, and is of human health concern. Hence, it is important to have sustainable amounts of the causative toxins available for toxicological studies and for instrument calibration in monitoring programs, without having to rely on natural toxin events. Continuous pilot scale culturing was carried out to evaluate the feasibility of AZA production using Azadinium spinosum cultures. Algae were harvested using tangential flow filtration or continuous centrifugation. AZAs were extracted using solid phase extraction (SPE) procedures, and subsequently purified. When coupling two stirred photobioreactors in series, cell concentrations reached 190,000 and 210,000 cell·mL−1 at...
Tipo: Text
Palavras-chave: Solid phase extraction; Photobioreactor; Chemostat; Dinoflagellate; Micro-algae; LC-MS/MS; Tangential flow filtration; Azaspiracid; HP-20.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00088/19875/17526.pdf

Study on the microalgal pigments extraction process: Performance of microwave assisted extraction
Provedor de dados: 5
Autores: Pasquet, Virginie; Cherouvrier, Jean-rene; Farhat, Firas; Thiery, Valerie; Piot, Jean-marie; Berard, Jean-baptiste; Kaas, Raymond; Serive, Benoit; Patrice, Thierry; Cadoret, Jean-paul; Picot, Laurent.
The performance of microwaves irradiation (MAE and VMAE) to extract pigments from two marine microalgae was compared to conventional processes (cold and hot soaking and ultrasound-assisted extraction). Pigments were quantified by RP-HPLC and extraction performance was assessed regarding rapidity, reproducibility and extraction yields. Scanning electron microscopy was used at all extraction steps to assess the impact of the process on microalgal cell integrity. Freeze-drying and pigments extraction preserved microalgae cell integrity (except sonication) and evoked agglutination in superposed cells layers. All processes performed on Dunaliella tertiolecta (chlorophyte) lead to rapid pigments extraction, and equivalent pigments extraction yields, the absence...
Tipo: Text
Palavras-chave: Pigments; Microalgae; Microwave; Extraction; Chlorophyll; Fucoxanthin; Carotene; MAE; VMAE.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00029/14059/11533.pdf

Use of a lipid rich strain reveals mechanisms of nitrogen limitation and carbon partitioning in the haptophyte Tisochrysis lutea
Provedor de dados: 5
Autores: Garnier, Matthieu; Bougaran, Gael; Pavlovic, Marija; Berard, Jean-baptiste; Carrier, Gregory; Charrier, Aurelie; Le Grand, Fabienne; Lukomska, Ewa; Rouxel, Catherine; Schreiber, Nathalie; Cadoret, Jean-paul; Rogniaux, Helene; Saint-jean, Bruno.
Haptophytes are a diverse monophyletic group with a worldwide distribution, known to be significantly involved in global climate regulation in their role as a carbon sink. Because nitrogen is a major limiting macronutrient for phytoplankton in oceans and for cultures of microalgae, understanding the involvement of nitrogen availability in haptophyte carbon partitioning is of global and biotechnological importance. Here, we made an ecophysiological study coupled with comprehensive large scale proteomic analysis to examine differences of behavior in reaction to nitrogen availability changes between a wild type strain of Tisochrysis lutea (WTc1) and a mutant strain (2Xc1) known to accumulate more storage lipids. Strains were grown in chemostats and studied...
Tipo: Text
Palavras-chave: Algae; Isochrysis; Lipids; Nitrogen; Reverse genomic: proteomic.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00356/46702/46904.pdf

Antiproliferative Activity of Cyanophora paradoxa Pigments in Melanoma, Breast and Lung Cancer Cells
Provedor de dados: 5
Autores: Baudelet, Paul-hubert; Gagez, Anne-laure; Berard, Jean-baptiste; Juin, Camille; Bridiau, Nicolas; Kaas, Raymond; Thiery, Valerie; Cadoret, Jean-paul; Picot, Laurent.
The glaucophyte Cyanophora paradoxa (Cp) was chemically investigated to identify pigments efficiently inhibiting malignant melanoma, mammary carcinoma and lung adenocarcinoma cells growth. Cp water and ethanol extracts significantly inhibited the growth of the three cancer cell lines in vitro, at 100 mu g.mL(-1). Flash chromatography of the Cp ethanol extract, devoid of c-phycocyanin and allophycocyanin, enabled the collection of eight fractions, four of which strongly inhibited cancer cells growth at 100 mu g.mL(-1). Particularly, two fractions inhibited more than 90% of the melanoma cells growth, one inducing apoptosis in the three cancer cells lines. The detailed analysis of Cp pigment composition resulted in the discrimination of 17 molecules, ten of...
Tipo: Text
Palavras-chave: Pigments; Microalgae; Cyanophora paradoxa; Melanoma; Cancer; Apoptosis; Zeaxanthin; Cryptoxanthin.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00177/28818/27289.pdf

Antiproliferative Activity of Violaxanthin Isolated from Bioguided Fractionation of Dunaliella tertiolecta Extracts
Provedor de dados: 5
Autores: Pasquet, Virginie; Morisset, Perrine; Ihammouine, Said; Chepied, Amandine; Aumailley, Lucie; Berard, Jean-baptiste; Serive, Benoit; Kaas, Raymond; Lanneluc, Isabelle; Thiery, Valerie; Lafferriere, Mathieu; Piot, Jean-marie; Patrice, Thierry; Cadoret, Jean-paul; Picot, Laurent.
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT dichloromethane extract exhibited a strong anti-proliferative activity on MCF-7 and LNCaP cells, and was further fractionated and sub-fractionated by RP-HPLC. High resolution mass spectrometry and spectrophotometric analysis unequivocally identified violaxanthin as the most antiproliferative molecule present in DT DCM extract. Violaxanthin purified from DT induced MCF-7 dose- dependent growth inhibition in continuous and discontinuous treatments, at...
Tipo: Text
Palavras-chave: Pigments; Microalgae; Dunaliella; Violaxanthin; Carotenoid; Cancer; Apoptosis.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00040/15142/12575.pdf

High-affinity nitrate/nitrite transporter genes (Nrt2) in Tisochrysis lutea: identification and expression analyses reveal some interesting specificities of Haptophyta microalgae
Provedor de dados: 5
Autores: Charrier, Aurelie Georgette; Berard, Jean-baptiste; Bougaran, Gael; Carrier, Gregory; Lukomska, Ewa; Schreiber, Nathalie; Fournier, Flora; Charrier, Aurelie; Rouxel, Catherine; Garnier, Matthieu; Cadoret, Jean-paul; Saint-jean, Bruno.
Microalgae have a diversity of industrial applications such as feed, food ingredients, depuration processes and energy. However, microalgal production costs could be substantially improved by controlling nutrient intake. Accordingly, a better understanding of microalgal nitrogen metabolism is essential. Using in silico analysis from transcriptomic data concerning the microalgae Tisochrysis lutea, four genes encoding putative high-affinity nitrate/nitrite transporters (TlNrt2) were identified. Unlike most of the land plants and microalgae, cloning of genomic sequences and their alignment with complementary DNA (cDNA) sequences did not reveal the presence of introns in all TlNrt2 genes. The deduced TlNRT2 protein sequences showed similarities to NRT2...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00253/36467/35044.pdf

Behavioural and biochemical responses of two marine invertebrates Scrobicularia plana and Hediste diversicolor to copper oxide nanoparticles
Provedor de dados: 5
Autores: Buffet, Pierre-emmanuel; Tankoua, Olivia Fossi; Pan, Jin-fen; Berhanu, Deborah; Herrenknecht, Christine; Poirier, Laurence; Amiard-triquet, Claude; Amiard, Jean-claude; Berard, Jean-baptiste; Risso, Christine; Guibbolini, Marielle; Romeo, Michele; Reip, Paul; Valsami-jones, Eugenia; Mouneyrac, Catherine.
Engineered nano-sized Cu oxide particles are extensively used in diverse applications. Because aquatic environments are the ultimate "sink" for all contaminants, it is expected that nanoparticles (NP) will follow the same fate. In this study, two marine invertebrates Scrobicularia plana and Hediste diversicolor were chosen as ecotoxicological models. The aim was to evaluate behavioural (burrowing kinetics, feeding rate) and biochemical (biomarkers) responses of S. plana and H. diversicolor exposed in the laboratory to Cu (10 mu g L(-1)) added in natural seawater either in the form of engineered nanoparticles (NPs) of CuO or as dissolved Cu in 2% HNO(3). Exposure was characterized by considering (i) the physico-chemical fate of NP (ii) the fraction of...
Tipo: Text
Palavras-chave: Copper oxide nanoparticles; Behaviour; Biomarkers; Oxidative stress; Scrobicularia plana; Hediste diversicolor.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00040/15140/15856.pdf

UPLC-MSE Profiling of Phytoplankton Metabolites: Application to the Identification of Pigments and Structural Analysis of Metabolites in Porphyridium purpureum
Provedor de dados: 5
Autores: Juin, Camille; Bonnet, Antoine; Nicolau, Elodie; Berard, Jean-baptiste; Devillers, Romain; Thiery, Valerie; Cadoret, Jean-paul; Picot, Laurent.
A fast and high-resolution UPLC-MSE analysis was used to identify phytoplankton pigments in an ethanol extract of Porphyridium purpureum (Pp) devoid of phycobiliproteins. In a first step, 22 standard pigments were analyzed by UPLC-MSE to build a database including retention time and accurate masses of parent and fragment ions. Using this database, seven pigments or derivatives previously reported in Pp were unequivocally identified: beta,beta-carotene, chlorophyll a, zeaxanthin, chlorophyllide a, pheophorbide a, pheophytin a, and cryptoxanthin. Minor amounts of Divinyl chlorophyll a, a chemotaxonomic pigment marker for prochlorophytes, were also unequivocally identified using the database. Additional analysis of ionization and fragmentation patterns...
Tipo: Text
Palavras-chave: Carotenoid; Chlorophyll; Dereplication; Divinyl chlorophyll a; Galactosyldiacylglycerol; Gracilamide; Mass spectrometry; MSE; Phytoplankton; Pigment; Porphyridium purpureum; UPLC.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00269/37994/36069.pdf

Modelling the accumulation of PSP toxins in Thau Lagoon oysters (Crassostrea gigas) from trials using mixed cultures of Alexandrium catenella and Thalassiosira weissflogii
Provedor de dados: 5
Autores: Lassus, Patrick; Amzil, Zouher; Baron, Regis; Sechet, Veronique; Barille, Laurent; Abadie, Eric; Bardouil, Michele; Sibat, Manoella; Truquet, Philippe; Berard, Jean-baptiste; Gueguen, Marielle.
In October and November 2003 a bloom of the toxic dinoflagellate Alexandrium catenella was observed in the North-east zone of Thau lagoon (French Mediterranean coast). Sea water samples were collected every hours to evaluate time-related variations of phytoplankton concentrations and to compare the relative ratio of A. catenella versus other phytoplankton species during the outbreak. From these observations, trials using recirculated sea water systems were performed to: i) evaluate the physiological effects on oyster of increasing proportions of A. catenella within a mixed microalgal diet where the non-toxic diatom Thalassiosira weissflogii was present at concentration: 1500 cells ml(-1), ii) compare the effect of two temperatures (12 degrees C and 18...
Tipo: Text
Palavras-chave: Mediterranean Sea; Alexandrium catenella; Toxin content; Model; Crassostrea gigas; Paralytic shellfish poisoning.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2624.pdf

Antimelanoma activity of Heterocapsa triquetra pigments
Provedor de dados: 5
Autores: Haguet, Quentin; Bonnet, Antoine; Berard, Jean-baptiste; Goldberg, Joelle; Joguet, Nicolas; Fleury, Audrey; Thiery, Valerie; Picot, Laurent.
Heterocapsa triquetra (Ht), a non-toxic dinophyte, was selected to investigate the presence of pigments inhibiting melanoma cells growth. We developed an innovative microwave-assisted extraction process (MAE), determined the Ht pigment composition using Reverse Phase-High Performance Liquid Chromatography (HPLC) and high-resolution Ultra Performance Liquid Chromatography-Mass Spectrometry E (UPLC-MSE) analysis and assessed their antiproliferative activity in human invasive melanoma cells (A2058) grown in vitro. MAE allowed a fast and efficient extraction of Ht pigments as compared with conventional processes (soaking, sonication). Seventeen pigments and derivatives were unequivocally identified by UPLC-MSᴱ in the Ht extract, among which two were supposed...
Tipo: Text
Palavras-chave: Dinophyte; Heterocapsa; Melanoma; Microalgae; Microwave assisted extraction; Pigment.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00390/50127/50806.pdf

Microwave-assisted extraction of phycobiliproteins from Porphyridium purpureum
Provedor de dados: 5
Autores: Juin, Camille; Cherouvrier, Jean-rene; Thiery, Valerie; Gagez, Anne-laure; Berard, Jean-baptiste; Joguet, Nicolas; Kaas, Raymond; Cadoret, Jean-paul; Picot, Laurent.
In the present study, microwave-assisted extraction was first employed to extract the phycobiliproteins of Porphyridium purpureum (Pp). Freeze-dried Pp cells were subjected to microwave-assisted extraction (MAE) to extract phycoerythin (PE), phycocyanin (PC), and allophycocyanin (APC). MAE combined reproducibility and high extraction yields and allowed a 180- to 1,080-fold reduction of the extraction time compared to a conventional soaking process. The maximal PE extraction yield was obtained after 10-s MAE at 40 A degrees C, and PE was thermally damaged at temperatures higher than 40 A degrees C. In contrast, a flash irradiation for 10 s at 100 A degrees C was the best process to efficiently extract PC and APC, as it combined a high temperature necessary...
Tipo: Text
Palavras-chave: Allophycocyanin; MAE; Microalgae; Microwave; Phycobiliprotein; Phycocyanin; Phycoerythrin; Porphyridium; Thylakoid.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00253/36439/35169.pdf

Zeaxanthin from Porphyridium purpureum induces apoptosis in human melanoma cells expressing the oncogenic BRAF V600E mutation and sensitizes them to the BRAF inhibitor vemurafenib
Provedor de dados: 5
Autores: Juin, Camille; De Oliveira Junior, Raimundo Gonsalves; Fleury, Audrey; Oudinet, Chloe; Pytowski, Lior; Berard, Jean-baptiste; Nicolau, Elodie; Thiery, Valerie; Lanneluc, Isabelle; Beaugeard, Laureen; Prunier, Gregoire; Guedes Da Silva Almeida, Jackson Roberto; Picot, Laurent.
Zeaxanthin, an abundant carotenoid present in fruits, vegetables and algae was reported to exert antiproliferative activity and induce apoptosis in human uveal melanoma cells. It also inhibited uveal melanoma tumor growth and cell migration in nude mice xenograft models. Here we report that zeaxanthin purified from the rhodophyte Porphyridium purpureum (Bory) K.M.Drew &amp; R.Ross, Porphyridiaceae, promotes apoptosis in the A2058 human melanoma cell line expressing the oncogenic BRAF V600E mutation. Zeaxanthin 40 μM (IC50) induced chromatin condensation, nuclear blebbing, hypodiploidy, accumulation of cells in sub-G1 phase, DNA internucleosomal fragmentation and activation of caspase-3. Western blot analysis revealed that zeaxanthin induced up-regulation...
Tipo: Text
Palavras-chave: Cancer; Carotenoid; Melanoma; Microalgae; Phytoplankton; Zeaxanthin.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00444/55595/57227.pdf