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| Registros recuperados: 29 | |
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| Castaing, Jean-baptiste; Masse, A.; Sechet, Veronique; Sabiri, N. -e.; Pontie, M.; Haure, Joel; Jaouen, P.. |
| In this study, an original use of immersed microfiltration membranes (mean pore size equal to 0.2 mu m) is investigated for the total removal of toxic dinoflagellates from seawater. Using a membrane autopsy and fouling model approach and the use of fouling indexes (called Pore Blocking Index, Pore Constriction Index and Cake Filtration Index), three dinoflagellate suspensions (Heterocapsa triquetra, Alexandrium minutum and Prorocentrum lima) have been microfiltered in order to study the influence of micro-algal species and its concentrations (1,000 and 30,000 cells/mL) on filtration yield and membrane fouling mechanisms. Results showed that all micro-algae have been retained after 180 min of microfiltration. At 30,000 cells/mL, permeate fluxes declined... |
| Tipo: Text |
Palavras-chave: Red tide; Dinoflagellate; Microfiltration; Membrane fouling mechanisms; Semi-closed aquaculture basins. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15246/14016.pdf |
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| Percopo, Isabella; Siano, Raffaele; Rossi, Rachele; Soprano, Vittorio; Sarno, Diana; Zingone, Adriana. |
| A new photosynthetic planktonic marine dinoflagellate, Azadinium dexteroporum sp. nov., is described from the Gulf of Naples (South Tyrrhenian Sea, Mediterranean Sea). The plate formula of the species, Po, cp, X, 4, 3a, 6, 6C, 5?S, 6'" and 2, is typical for this recently described genus. Azadinium dexteroporum is the smallest rep-resentative of the genus (8.5m average length, 6.2m average width) and shares the presence of a small antapical spine with the type species A.spinosum and with A.polongum. However, it differs from all other Azadinium species for the markedly asymmetrical Po plate and the position of the ventral pore, which is located at the right posterior end of the Po plate. Another peculiarity of A.dexteroporum is the pronounced concavity of... |
| Tipo: Text |
Palavras-chave: Azadinium; Azaspiracid; Dinoflagellate; LC; MS-TOF; LTER-MC; Mediterranean Sea; Phylogeny; Taxonomy. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00171/28199/27278.pdf |
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| Jauzein, Cecile; Couet, Douglas; Blasco, Thierry; Lemee, Rodolphe. |
| Environmental factors that shape dynamics of benthic toxic blooms are largely unknown. In particular, for the toxic dinoflagellate Ostreopsis cf. ovata, the importance of the availability of nutrients and the contribution of the inorganic and organic pools to growth need to be quantified in marine coastal environments. The present study aimed at characterizing N-uptake of dissolved inorganic and organic sources by O. cf. ovata cells, using the 15N-labelling technique. Experiments were conducted taking into account potential interactions between nutrient uptake systems as well as variations with the diel cycle. Uptake abilities of O. cf. ovata were parameterized for ammonium (NH4+), nitrate (NO3−) and N-urea, from the estimation of kinetic and inhibition... |
| Tipo: Text |
Palavras-chave: Uptake; Nitrogen; Dinoflagellate; Ostreopsis; Kinetics; Interactions. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00382/49368/49840.pdf |
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| Penaud, Aurelie; Hardy, William; Lambert, Clement; Marret, Fabienne; Masure, Edwige; Seryais, Thomas; Siano, Raffaele; Wary, Melanie; Mertens, Kenneth. |
| Dinoflagellates are part of the marine plankton and about 200 species produce a cyst (dinocyst) during their life cycle, these organic-walled sexually-produced cysts being fossilizable in sediments for hundreds of millions of years. Over the past 40–50 years, dinocysts have led to major advances on Mesozoic-Cenozoic research, in terms of biostratigraphy and paleogeogeography. Dinocyst taxonomy has then been continuously revised, with the tabulation being the main morphological link between living dinoflagellates and fossilized cysts. Over the Quaternary, and based on the principle of uniformitarianism (i.e. species ecology did not change through time), relationships between modern assemblages and present-day environmental factors controlling their... |
| Tipo: Text |
Palavras-chave: Dinoflagellate; Cyst-motile stage relationship; Modern dinocyst distribution; Paleoecology; Biostratigraphy; Ancient DNA. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57476/59749.pdf |
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| Delebecq, Gaspard; Schmidt, Sabine; Ehrhold, Axel; Latimier, Marie; Siano, Raffaele. |
| The biological processes involved in the preservation, viability, and revival of long‐term dormant dinoflagellate cysts buried in sediments remain unknown. Based on studies of plant seed physiology, we tested whether the revival of ancient cysts preserved in century‐old sediments from the Bay of Brest (France) could be stimulated by melatonin and gibberellic acid, two molecules commonly used in seed priming. Dinoflagellates were revived from sediments dated to approximately 150 years ago (156 ± 27, 32 cm depth), extending the known record age of cyst viability previously established as around one century. A culture suspension of sediments mixed with melatonin and gibberellic acid solutions as biostimulants exhibited germination of 11 dinoflagellate taxa... |
| Tipo: Text |
Palavras-chave: Alexandrium; Cyst; Dinoflagellate; Gibberellic acid; Melatonin; Paleoecology; Priming; Scrippsiella; Resurrection ecology. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73960/73321.pdf |
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| Gas, F; Pinto, L; Baus, B; Gaufres, L; Crassous, Marie-pierre; Compere, Chantal; Quemeneur, E. |
| Harmful algal blooms represent a major threat to marine production, and particularly to shellfish farming. Alexandrium minutum, which causes paralytic shellfish poisoning, is occurring with increasing frequency along European coasts. Current regulatory methods to analyze environmental samples are tedious and time consuming because they require taxonomists and involve animal experiments. New rapid detection methods, such as immunoassays, are needed to ensure a fast alert system and for field studies of algal ecodynamics. Rat monoclonal antibodies were raised and selected for their ability to specifically recognize a surface antigen for the A. minutum strain AM89BM from the Bay of Morlaix, France. A whole-cell ELISA was designed, leading to the selection of... |
| Tipo: Text |
Palavras-chave: Monoclonal antibody; Harmful algal bloom; Enzyme linked immunosorbent assay; Dinoflagellate. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4647.pdf |
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| 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 |
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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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| Le Bec, Claude; Legendre, Aurelie; Messiaen, Gregory. |
| Time series of physico-chemical data and concentrations (cell L-1) of the toxic dinoflagellate Alexandrium minutum collected in the Rance macrotidal estuary (Brittany, France) were analyzed to understand the physico-chemical processes of the estuary and their relation to changes in bloom development from 1996 to 2009. The construction of the tidal power plant in the north and the presence of a lock in the south have greatly altered hydrodynamics, blocking the zone of maximum turbidity upstream, in the narrowest part of the estuary. Alexandrium minutum occurs in the middle part of the estuary. Most physical and chemical parameters of the Rance estuary are similar to those observed elsewhere in Brittany with water temperatures between 15–18 °C, slightly... |
| Tipo: Text |
Palavras-chave: Harmful algae; Dinoflagellate; Nutrients; Eutrophication; Drainage basin; Land runoff. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00341/45257/44698.pdf |
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| Thoha, Hikmah; Muawanah,; Bayu Intan, Mariana D.; Rachman, Arief; Sianturi, Oksto Ridho; Sidabutar, Tumpak; Iwataki, Mitsunori; Takahashi, Kazuya; Avarre, Jean-christophe; Masseret, Estelle. |
| Margalefidinium polykrikoides, an unarmored dinoflagellate, was suspected to be the causative agent of the harmful algal blooms – associated with massive fish mortalities – that have occurred continually in Lampung Bay, Indonesia, since the first bloom event in October 2012. In this study, after examination of the morphology of putative M. polykrikoides-like cysts sampled in bottom sediments, cyst bed distribution of this harmful species was explored in the inner bay. Sediment samples showed that resting cysts, including several morphotypes previously reported as M. polykrikoides, were most abundant on the northern coast of Lampung Bay, ranging from 20.6 to 645.6 cysts g-1 dry sediment. Molecular phylogeny inferred from LSU rDNA revealed that the so-called... |
| Tipo: Text |
Palavras-chave: Margalefidinium polykrikoides; Dinoflagellate; Harmful algal blooms; Resting and hyaline cysts; Indonesia. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60086/63423.pdf |
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| Jauffrais, Thierry; Contreras, Andrea; Herrenknecht, Christine; Truquet, Philippe; Sechet, Veronique; Tillmann, Urban; Hess, Philipp. |
| Azadinium spinosum, a small toxic dinoflagellate, was recently isolated and identified as a primary producer of azaspiracid toxins (AZAs). Previous experiments related to AZA accumulation in blue mussels upon direct feeding with A. spinosum revealed increased mussel mortality and had negative effects on the thickness of the digestive gland tubules. Therefore we conducted follow up experiments in order to study effects of A. spinosum on mussel feeding behaviour. Individual assessment of mussel feeding time activity (FTA), clearance rate (CR), filtration rate (TFR), absorption rate (AR), faeces and pseudofaeces production were carried out on mussel fed either toxic (A. spinosum) or non-toxic (Isochrisis aff. galbana (T-Iso)) diets. Furthermore, AZA... |
| Tipo: Text |
Palavras-chave: Bivalve molluscs; Mussel; Ecophysiology; AZA biotransformation; AZA accumulation; Trophic transfer; Dinoflagellate; Azaspiracid. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00090/20174/17832.pdf |
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| Zhang, Wei; Li, Zhun; Mertens, Kenneth; Derrien, Amelie; Pospelova, Vera; Carbonell-moore, M. Consuelo; Bagheri, Siamak; Matsuoka, Kazumi; Shin, Hyeon Ho; Gu, Haifeng. |
| Gonyaulax verior was initially described as Amylax diacantha from Belgian coastal waters a century ago but its detailed morphology needed restudy. Here, we established nine strains of G. verior by germinating cysts or isolating cells from localities from the European Atlantic to the Caspian Sea and the Pacific Ocean. Both cyst and thecal morphology were examined by light and scanning electron microscopy. SSU, LSU and/or ITS-5.8S rRNA gene sequences were obtained from all strains. Cells of G. verior have a plate formula of Po, 4′, 2a, 6-7′′, 6C, 6S, 6′′′, 1p, 1′′′′ with an L-type ventral organisation, characterised by two either straight or curved antapical horns of variable length. Cysts of G. verior are oval, smooth and contain one or two yellow... |
| Tipo: Text |
Palavras-chave: Amylax diacantha; Cysts; Dinoflagellate; Gonyaulax longispina; Molecular phylogeny. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00621/73347/72625.pdf |
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| Tichadou, Lucia; Glaizal, Mathieu; Armengaud, Alexis; Grossel, Hubert; Lemee, Rodolphe; Kantin, Roger; Lasalle, Jean-luc; Drouet, Geneveve; Rambaud, Loic; Malfait, Philippe; De Haro, Luc. |
| Objective. Ostreopsis ovata and Ostreopsis siamensis are tropical unicellular algae that have been found recently in the Mediterranean. Both of these dinoflagellates produce palytoxin (PTX)-like toxins that are powerful vasoconstrictors in mammals. Since 2003, Ostreopsis blooms in Italy and Spain have been accompanied by reports of respiratory problems and skin/mucosa irritation in persons in contact with toxic microalgal cells (epiphytes, plankton, or sea spray) or associated toxins. Methods. In France, a surveillance network has been set up to monitor water conditions and to protect swimmers from contamination due to Ostreopsis. Results. Between 2006 and 2009, a total of nine blooms were observed on the French Mediterranean coast including five that led... |
| Tipo: Text |
Palavras-chave: Dinoflagellate; Algal bloom; Ostreopsis; Mediterranean Sea; Palytoxin. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00016/12716/9694.pdf |
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| Jauffrais, Thierry; Herrenknecht, Christine; Sechet, Veronique; Sibat, Manoella; Tillmann, Urban; Krock, Bernd; Kilcoyne, Jane; Miles, Christopher O.; Mccarron, Pearse; Amzil, Zouher; Hess, Philipp. |
| Azaspiracids (AZAs) are secondary metabolites of Azadinium spinosum, that have been shown to cause diarrhetic shellfish poisoning when accumulated in bivalve molluscs. We describe here an analytical procedure for the determination of AZAs in cultures of A. spinosum with a focus on the potential formation of AZA methyl-esters as artefacts in the extraction and sample pre-treatment. A. spinosum cells were collected from bioreactor cultures, using centrifugation or filtration. Different extraction procedures were evaluated for formation of methyl-ester artefacts, yield, and matrix effects. Filtration of cultures using glass-fibre filters led to increased formation of methyl-esters. Hence centrifugation is recommended for recovery of cells. The type of... |
| Tipo: Text |
Palavras-chave: Extraction procedure; Extraction artefact; Matrix effects; LC-MS/MS; Azaspiracid methyl ester; Dinoflagellate; Liquid chromatography-mass spectrometry. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00077/18812/16463.pdf |
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| Shaked, Yonathan; De Vargas, Colomban. |
| We present large subunit (LSU) and internal transcribed spacer (ITS) rDNA based phylogenies of symbiotic dinoflagellates retrieved from single-cell planktonic foraminifera collected around the world. All modern foraminiferal species involved in such symbiosis are included in our analyses. The pelagic symbiotic dinoflagellates form a monophyletic group sister to the Symbiodinium species complex found in coastal-benthic environments. The pelagic symbionts are descendants of free-living species and, together with the coastal-benthic Symbiodinium spp., they originated from the early Mesozoic suessiacean family represented by the extant Polarella glacialis. Out of hundreds of single planktonic foraminifera examined, 21 unique pelagic symbiont ribotypes were... |
| Tipo: Text |
Palavras-chave: Symbiosis; Planktonic foraminifer; Dinoflagellate; Open ocean; Suessiales. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00383/49440/49907.pdf |
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| Registros recuperados: 29 | |
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