Consulta: creatorFacets:"Crassous, Marie-pierre"
Registros recuperados: 19
Data/hora: 03/06/2024 07:57:49

Toward in situ detection of algae species
Provedor de dados: 5
Autores: Colas, Florent; Laurent, Sebastien; Lehaitre, Michel; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Dreanno, Catherine; Deuff, Albert; Compere, Chantal.
For the last few years there is a more and more pressing need to develop system for detecting HAB at their early stage. Researchers have then been working on new in situ sensor. In this paper a submarine transducer based on surface plasmon resonance is reported. It demonstrated a refractive index resolution of 3.10(-6), which is promising for later phytoplankton detection.
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21802/20328.pdf

Optimisation de l’identification et du dénombrement du microphytoplancton avec le système couplé de numérisation et d’analyse d’images FlowCAM – Zoo/PhytoImage (système innovant). Action 9 – Livrable 3. Evolution du matériel de numérisation : prototype FastCAM et perspectives. Rapport final, février 2016
Provedor de dados: 5
Autores: Colas, Florent; Tardivel, Morgan; Evrard, Justine; Forest, Bertrand; Crassous, Marie-pierre; Lunven, Michel; Danielou, Marie-madeleine.
This deliverable contains all development work of the FastCAM, new tool for fast imaging of the phytoplankton, which took place in 2015. It consists of: One report of the FastCAM and its comparison with the FlowCAM presentation: The FlowCAM enables the digitalization of a sample of phytoplankton with X10 and X 4 magnifications. The first allows a better morphological description and therefore a higher taxonomic resolution but with a longer scan time (16 X). Thus, for routine analyses, only scanning at 4 X is possible. A considerable gain would be able to do an acquisition to the magnification 10 X with a time of analysis more short, comparable to 4 X. A fast flow imaging system has therefore developed in this sense. He was called FastCAM. The system is...
Tipo: Text
Palavras-chave: FlowCAM; FastCAM; Imagerie rapide; Phytoplancton; REPHY.; FlowCAM; FastCAM; Fast imaging; Phytoplankton; REPHY.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00363/47420/47425.pdf

Nutrient and phytoplankton distribution in the Loire River plume (Bay of Biscay, France) resolved by a new Fine Scale Sampler
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain.
A new Fine Scale Sampler (FSS) was designed and used in the Loire River plume (Bay of Biscay, France) in order to study phytoplankton distribution in highly stratified water columns. The FSS consists of a linear array of 15 sampling bottles, set horizontally at 20 cm intervals. Data acquired from the CTD and fluorescence probe of the FSS enable it to be precisely positioned at the depth of the highest density gradient or at the chlorophyll a maximum. The FSS made it possible to investigate fine scale vertical distribution of phytoplankton and relationships with water density, nutrient concentrations or light availability, for spring and summer conditions. Under spring conditions, the entire upper layer exhibited a dominant diatom population (Chaetoceros...
Tipo: Text
Palavras-chave: Plankton patchiness; Density discontinuity; Sampling; Thin layer; Nutrients; Phytoplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-533.pdf

Comparaison de l'hétérotrophie phytoplanctonique en laboratoire et in situ : efflorescence estivale en eau côtière et populations printanières en mer stratifiée
Provedor de dados: 5
Autores: Arzul, Genevieve; Videau, Christiane; Bodennec, Guy; Crassous, Marie-pierre; Youenou, Agnes.
Pour mieux connaître les facteurs qui agissent sur les interactions trophiques entre le phytoplancton et le milieu nutritif, nous avons étudié la capacité hétérotrophe du phytoplancton en conditions contrôlées, non axéniques, au laboratoire. Les expériences réalisées avec la [U-14C] glutamine, étaient basées sur l'étude des vitesses d'assimilation. Les résultats obtenus avec deux espèces du genre Gymnodinium et une diatomée ont été vérifiés lors d'efflorescences en eau côtière et estuarienne, montrant l'adaptation des algues au milieu riche en substances organiques et leur capacité hétérotrophe en fonction de l'éclairement. L'effet de l'éclairement sur la capacité phagotrophe de Gymnodinium a été observé au laboratoire. L'étude réalisée sur les particules...
Tipo: Text
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00105/21599/19179.pdf

Toward Detection of Harmful Algae Blooms by in situ Surface Plasmon Resonance Spectroscopy
Provedor de dados: 5
Autores: Laurent, Sebastien; Colas, Florent; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Lehaitre, Michel; Compere, Chantal.
Among marine algae species, Alexandrium minutum produces a phycotoxin called paralytic shellfish poisoning (PSP) that is introduced in the food chain through the ingestion of phytoplankton by shellfishs, and later by human consumers. Thus, in situ monitoring of A. minutum proliferation in coastal seawater is of great economical importance for marine resources exploitation. Here, we propose a rapid test for the detection of A. minutum by surface plasmon resonance spectroscopy. First, whole genomic DNA is extracted from the algae. Second, a 677 bp long portion of the 28S ribosomal DNA is amplified by PCR. Third, the PCR product is detected by surface plasmon resonance spectroscopy onto a DNA functionalized gold substrate.
Tipo: Text
Palavras-chave: PCR; Algal detection; In situ; Spectroscopy; Surface plasmon resonance.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6830.pdf

Competition for phosphorus between two dinoflagellates: A toxic Alexandrium minutum and a non-toxic Heterocapsa triquetra
Provedor de dados: 5
Autores: Labry, Claire; Erard-le Denn, Evelyne; Chapelle, Annie; Fauchot, Juliette; Youenou, Agnes; Crassous, Marie-pierre; Le Grand, Jacqueline; Lorgeoux, Benedicte.
The understanding of the dominance of one species with respect to others is a pertinent challenge in HAB growth dynamics studies and the nutrient supply mode is one of the factors potentially involved. The competition for phosphorus (P) between a toxic species, Alexandrium minutum, and a non-toxic species, Heterocapsa triquetra, was studied (1) along a gradient of P depletion, (2) testing different P depletion degrees before a single PO4 supply and (3) experimenting different PO4 supply frequencies. In conditions Of PO4 depletion, H. triquetra stopped growing after two days both in monospecific and mixed batch cultures whereas A. minutum grew progressively from day 2 until the end of the experiment. This time-lag growth of A. minutum is associated to its...
Tipo: Text
Palavras-chave: Semi continuous culture; Batch culture; Ecophysiology; Pulse; Phosphorus storage; Dinoflagellates; Heterocapsa triquetra; Alexandrium minutum.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4067.pdf

Monoclonal antibody against the surface of Alexandrium minutum used in a whole-cell ELISA
Provedor de dados: 5
Autores: 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

Detection and molecular identification of Pseudo-nitzschia species in natural samples from the French coasts
Provedor de dados: 5
Autores: Perez Blanco, Eva; Antoine, Elisabeth; Crassous, Marie-pierre; Compere, Chantal.
Domoic acid (DA) was first detected in France in mussel flesh in 1998, outbreak that was linked to the presence of Pseudo-nitzschia pseudodelicatissima. Ever since, the phytoplankton monitoring program (REPHY, Réseau de surveillance du Phytoplancton et des Phycotoxines) also monitors DA content in shellfish flesh. Amnesic shellfish poisoning (ASP) has been recurrently detected, and was over the sanitary threshold in the years 2000 and 2004 in Brittany and in 2002 in the Mediterranean coast (Amzil, 2001; Amzil pers. comm.). Toxicity events are usually dominated by several Pseudo-nitzschia species, although different strains might be or not be toxic (Bates et al., 1998). This is why an inventory of the species present in the French coasts and their molecular...
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00089/19988/17652.pdf

A surface plasmon resonance system for the underwater detection of domoic acid
Provedor de dados: 5
Autores: Colas, Florent; Crassous, Marie-pierre; Laurent, Sebastien; Litaker, Richard W.; Rinnert, Emmanuel; Le Gall, Erwan; Lunven, Michel; Delauney, Laurent; Compère, Chantal.
Over the past decade Surface Plasmon Resonance (SPR) techniques have been applied to the measurement of numerous analytes. In this article, an SPR biosensor system deployed from an oceanographic vessel was used to measure dissolved domoic acid (DA), a common and harmful phycotoxin produced by certain microalgae species belonging to the genus Pseudo-nitzschia. During the biosensor deployment, concentrations of Pseudo-nitzschia cells were very low over the study area and measured DA concentrations were below detection. However, the in situ operational detection limit of the system was established using calibrated seawater solutions spiked with DA. The system could detect the toxin at concentrations as low as 0.1 ng mL−1 and presented a linear dynamic range...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00324/43481/42921.pdf

Surveillance écologique et halieutique du site électronucléaire de Paluel - Année 2001. Rapport scientifique annuel
Provedor de dados: 5
Autores: Thillaye Du Boullay, Herve; Crassous, Marie-pierre; Davoult, Dominique; Delpech, Jean-paul; Dorobisz, Laurence; Maheux, Frank; Monbet, Philippe; Richard, I.; D'Elbee, Jean.
Monitoring no24 of the Paluel nuclear power plant takes into account studies conducted between March and September 2001. Impacts on hydrology, microbiology, phytoplankton, zooplankton, fis he ries, intertidal phytobenthos and zoobenthos are reported. This power plant has been in operation for eighteen years.
Tipo: Text
Palavras-chave: Centrale nucléaire Paluel Surveillance Halieutique Pelagos Benthos Paluel Monitoring Nuclear power plant; Benthos Fisheries Pelagos.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00083/19390/16984.pdf

Organometallic nanoprobe to enhance optical response on the polycyclic aromatic hydrocarbon benzo[a]pyrene immunoassay using SERS technology
Provedor de dados: 5
Autores: Dribek, Mohamed; Rinnert, Emmanuel; Colas, Florent; Crassous, Marie-pierre; Thioune, Nene; David, Catalina; De La Chapelle, Marc; Compere, Chantal.
We demonstrated the use of a new organometallic nanoprobe for competitive surface-enhanced Raman scattering (SERS) immunoassay devoted to the detection of polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (BaP) in seawater. The nanoprobes are gold nanoparticles (GNPs) labeled by a Raman reporter, the 5,5'-dithiobis(succinimidyl-2-nitrobenzoate) (DSNB) and functionalized with monoclonal antibodies anti-BaP. The antibodies are bound with a high specificity to the analyte while the GNPs enhanced the Raman scattering of the DSNB. This type of immunoassay involved the grafting of BaP onto a sensing surface. Thus, NH2-terminated self-assembled monolayer is formed on the surface of gold substrate using cysteamine. Amines finally reacted with...
Tipo: Text
Palavras-chave: Biosensor; Surface-enhanced Raman scattering; Polycyclic aromatic hydrocarbons; Benzo[a]pyrene antibody; Organometallic nanoprobe.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00417/52844/53870.pdf

Monoclonal antibody against the surface of alexandrium minutum used in a whole-cell ELISA (Poster)
Provedor de dados: 5
Autores: Gas, Fabienne; Pinto, Laetitia; Baus, Beatrice; Gaufres, Laure; Crassous, Marie-pierre; Compere, Chantal; Quemeneur, Eric.
PRODUCTION AND CHARACTERIZATION OF MONOCLONAL ANTIBODY ANTI-Alexandrium minutum
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00089/19994/17657.pdf

Biosensors for the detection and monitoring of Alexandrium minutum along the French coasts
Provedor de dados: 5
Autores: Antoine, Elisabeth; Compere, Chantal; Cosnier, Serge; Crassous, Marie-pierre; Derbal, Hassina; Erard-le Denn, Evelyne; Gondran, Chantal; Guilminot, Elodie; Lehaitre, Michel; Mazeas, Florence; Moreau, Hervé; Perrot, Hubert; Pradier, Claire-marie; Salmain, Michèle.
The microalgae Alexandrium minutum produces neurotoxins responsible for paralytic shellfish poisoning, which upon accumulation in shellfish represent a human health risk. This species recurrently forms toxic blooms in the Northern part of the French Brittany coast. At present, algae identification relies on tedious microscope observations mostly performed by skilled taxonomists in laboratories. Newly emerging fields of molecular taxonomy, nanoscale technology and biotechnology offer opportunities for the development of in-situ biosensors for the detection and the monitoring of toxic algae.
Tipo: Text
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00089/19986/17650.pdf

Organometallic nanoprobe to enhance optical response on Polycyclic Aromatic Hydrocarbons (PAHs) immunoassay using SERS technology
Provedor de dados: 5
Autores: Dribek, Mohamed; Rinnert, Emmanuel; Colas, Florent; Crassous, Marie-pierre; Compere, Chantal.
We demonstrate the possible use of organometallic nanoprobe on competitive surface-enhanced Raman scattering immunoassay for policyclic aromatic hydrocarbon detection in sea water. This type of SERS immunoassay is based on to capture Raman reporter-labeled immuno-Au onto the immobilized layer of antigens (benzo[a]pyrene) on the gold substrate after incubation of these nanoprobes with PAHs including in the sample. To realize nanoprobes, first we have prepared gold nanoparticles (GNPs) according to Frens’ method. Then, we have labeled GNPs by the Raman reporter of 5,5’-Dithiobis(succinimidyl-2-nitrobenzoate) (DSNB). Thereafter, Benzo[a]pyrene antibody was attached to the DSNB labeled GNPs. Before use in SERS detection, their activity was controlled by...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00088/19912/17576.pdf

Direct and fast detection of Alexandrium minutum algae by using high frequency microbalance
Provedor de dados: 5
Autores: Sousa, Celia; Compere, Chantal; Dreanno, Catherine; Crassous, Marie-pierre; Gas, Fabienne; Baus, Beatrice; Perrot, Hubert.
In this paper, a simple detection of a toxic algae, Alexandrium minutum, was developed using highly sensitive quartz crystal microbalance. In terms of performance, compared with other conventional analytical tools, the main interest of our immunosensor is based on a fast and direct detection of these living cells. This system requires the use of one monoclonal antibody directed against the surface antigen of A. minutum. We demonstrate that the whole living and motile algae are caught and detected. The high specificity of the biosensor is also demonstrated by testing several other dinoflagellate species. The frequency shift is correlated to the A. minutum cells concentration. This simple system is potentially promising for environmental monitoring purposes.
Tipo: Text
Palavras-chave: Alexandrium minutum; Quartz microbalance; Microalgae; Immunosensor.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00194/30492/28897.pdf

Motility and autotoxicity in Karenia mikimotoi (Dinophyceae)
Provedor de dados: 5
Autores: Gentien, Patrick; Lunven, Michel; Lazure, Pascal; Youenou, Agnes; Crassous, Marie-pierre.
Karenia mikimotoi is one of the most common red-tide dinoflagellates proliferating in the eastern North Atlantic and around Japan. Kills of marine fauna are associated with its blooms. In mixed water columns it migrates vertically, while in stratified water columns, the population remains confined within pycnocline layers. Wind events, increasing mixing and agitation initiate declines in its populations. This paper is focused on the formulation of mortality rate relative to shear rate. Autotoxicity is demonstrated by the use of a synthetic toxin. Bioconvection observed in cultures allows the establishment of a trade-off between phototropism, which leads to the local accumulation of cells, and their autotoxicity, which would prevent cell concentration. The...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2436.pdf

Vertical distribution of phytoplankton communities and relationships with physico-chemical parameters resolved by a fine scale sampler
Provedor de dados: 5
Autores: Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain.
Many studies in coastal areas have shown the existence of thin chemical and biological layers. Their thickness and vertical extension are mainly controlled by hydrological and physical forcing. An accurate description of the phytoplankton communities growing within these layers is difficult to obtain without a well-adapted sampling system. A new Fine Scale Sampler (FSS) has been designed in Ifremer in order to study phytoplankton distribution and associated dissolved properties in high stratified water column. This FSS consists in a vertical array of 15 sampling bottles, horizontally laid with 20 cm intervals. Data acquired from a CTD and Fluorescence probe provide a precise FSS positioning at the depth of highest density gradient or at chlorophyll a...
Tipo: Text
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxine.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00144/25493/23647.pdf

New Approach For The Detection Of Toxic Algae Species
Provedor de dados: 5
Autores: Colas, Florent; Crassous, Marie-pierre; Laurent, Sebastien; Dreanno, Catherine; Compere, Chantal.
Up to now, toxic species are monitored by expensive and time-consuming laboratory analysis of seawater samples: after a 24h decantation, the samples are observed with an optical microscope and the cell concentration per species is determined. In this context, systems able to detect HAB species directly underwater would be of great help. An assay based on an SPR biosensor was then developed for detecting Alexandrium minutum.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00089/19995/17658.pdf

Alexandrium minutum growth controlled by phosphorus An applied model
Provedor de dados: 5
Autores: Chapelle, Annie; Labry, Claire; Sourisseau, Marc; Lebreton, Carole; Youenou, Agnes; Crassous, Marie-pierre.
Toxic algae are a worldwide problem threatening aquaculture public health and tourism Alexandrium a toxic dinoflagellate proliferates in Northwest France estuaries (i e the Penze estuary) causing Paralytic Shellfish Poisoning events Vegetative growth and in particular the role of nutrient uptake and growth rate are crucial parameters to understand toxic blooms With the goal of modelling in situ Alexandrium blooms related to environmental parameters we first try to calibrate a zero-dimensional box model of Alexandrium growth This work focuses on phosphorus nutrition Our objective is to calibrate Alexandrium minutum as well as Heterocapsa triquetra (a non-toxic dinoflagellate) growth under different rates of phosphorus supply other factors being optimal and...
Tipo: Text
Palavras-chave: Toxic algal blooms; Alexandrium; Phosphorus uptake; Models; Competition; Northwest France.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00018/12901/9905.pdf