Consulta: creatorFacets:"Got, Patrice"
Registros recuperados: 10
Data/hora: 01/06/2024 13:29:49

Trophic relationships between metazooplankton communities and their plankton food sources in the Iles Eparses (Western Indian Ocean)
Provedor de dados: 5
Autores: Dupuy, Christine; Pagano, Marc; Got, Patrice; Domaizon, Isabelle; Chappuis, Alexis; Marchessaux, Guillaume; Bouvy, Marc.
Coral reef and atoll lagoons are among the most diversified marine ecosystems but also the most affected by the combined effects of climate change and human activities. The Iles Eparses (Scattered Islands) in the Western Indian Ocean have been little affected by human pressure and can be considered to be “pristine” ecosystems. Metazooplankton plays a major role in the functioning and productivity of aquatic ecosystems, and this study was undertaken: (i) to determine the spatial abundance, distribution and species composition of metazooplankton, (ii) to assess the effect of metazooplankton grazing on pico- and nanophytoplankton and (iii) to analyze the trophic positions of metazooplankton by using the stable isotope signatures of a wide variety of taxa and...
Tipo: Text
Palavras-chave: Metazooplankton; Spatial distribution; Grazing effect; Feeding ecology; Iles Eparses; Mayotte.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00317/42850/42259.pdf

Alterins Produced by Oyster-Associated Pseudoalteromonas are Antibacterial Cyclolipopeptides with LPS-Binding Activity
Provedor de dados: 5
Autores: Desriac, Florie; El Harras, Abderrafek; Simon, Matthieu; Bondon, Arnaud; Brillet, Benjamin; Le Chevalier, Patrick; Pugnière, Martine; Got, Patrice; Destoumieux-garzón, Delphine; Fleury, Yannick.
Discovery after discovery, host-associated microbiota reveal a growing list of positive effects on host homeostasis by contributing to host nutrition, improving hosts’ immune systems and protecting hosts against pathogens. In that context, a collection of oyster associated bacteria producing antibacterial compounds have been established to evaluate their role in non-host-derived immunity. Here, we described alterins; potent anti-Gram negative compounds produced by Pseudoalteromonas hCg-6 and hCg-42 isolated from different healthy oyster hemolymph. The strains hCg-6 and hCg-42 produce a set of at least seven antibacterial compounds, ranging from 926 to 982 Da structurally characterized as cyclolipopeptides (CLPs). Alterins share the same cationic...
Tipo: Text
Palavras-chave: Pseudoalteromonas; Cyclolipopeptides; Alterin; Antibiotic.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00663/77511/79275.pdf

Microbial Diversity and Cyanobacterial Production in Dziani Dzaha Crater Lake, a Unique Tropical Thalassohaline Environment
Provedor de dados: 5
Autores: Leboulanger, Christophe; Agogue, Helene; Bernard, Cecile; Bouvy, Marc; Carre, Claire; Cellamare, Maria; Duval, Charlotte; Fouilland, Eric; Got, Patrice; Intertaglia, Laurent; Lavergne, Celine; Le Floc'H, Emilie; Roques, Cecile; Sarazin, Gerard.
This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.614.5 g L-1 eq. CO32-, i.e. 160220 mM compare to around 22.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 mu g chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the...
Tipo: Text
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00625/73731/74808.pdf

The major outer membrane protein OmpU of Vibrio splendidus contributes to host antimicrobial peptide resistance and is required for virulence in the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Duperthuy, Marylise; Binesse, Johan; Le Roux, Frederique; Romestand, Bernard; Caro, Audrey; Got, Patrice; Givaudan, Alain; Mazel, Didier; Bachere, Evelyne; Destoumieux Garzon, Delphine.
Vibrio splendidus, strain LGP32, is an oyster pathogen associated with the summer mortalities affecting the production of Crassostrea gigas oysters worldwide. Vibrio splendidus LGP32 was shown to resist to up to 10 mu M Cg-Def defensin and Cg-BPI bactericidal permeability increasing protein, two antimicrobial peptides/proteins (AMPs) involved in C. gigas immunity. The resistance to both oyster Cg-Def and Cg-BPI and standard AMPs (polymyxin B, protegrin, human BPI) was dependent on the ompU gene. Indeed, upon ompU inactivation, minimal bactericidal concentrations decreased by up to fourfold. AMP resistance was restored upon ectopic expression of ompU. The susceptibility of bacterial membranes to AMP-induced damages was independent of the ompU-mediated AMP...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11421/8044.pdf

Structural and functional responses of coastal marine phytoplankton communities to PAH mixtures
Provedor de dados: 5
Autores: Ben Othman, Hiba; Lanouguere, Elodie; Got, Patrice; Hlaili, Asma Sakka; Leboulanger, Christophe.
The toxicity of polycyclic aromatic hydrocarbons (PAHs) mixtures was evaluated on natural phytoplankton communities sampled from lagoons of Bizerte (South-western Mediterranean Sea) and Thau (North-western Mediterranean Sea). PAHs induced short-term dose and ecosystem-dependant decreases in photosynthetic potential. Chlorophyll a was negatively affected by increasing PAHs concentrations, together with dramatic changes in phytoplankton community composition. Size classes were strongly affected in the Bizerte compare to the Thau lagoon, with a decrease in nano- and microphytoplankton densities compare to picophytoplankton. In both locations, the diatom Entomoneis paludosa appeared favoured under PAH exposure as evidenced by increase in cell density, whereas...
Tipo: Text
Palavras-chave: PAH mixtures (PAHs); Phytoplankton communities; Mediterranean coastal lagoons; Ecotoxicity.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00456/56801/58867.pdf

Rapid responses of pristine marine planktonic communities in experimental approach to diuron and naphthalene (Juan de Nova Island, Western Indian Ocean)
Provedor de dados: 5
Autores: Bouvy, Marc; Dupuy, Christine; Got, Patrice; Domaizon, Isabelle; Carré, Claire; Pagano, Marc; Debroas, Didier; Roques, Cécile; Leboulanger, Christophe.
Planktonic communities from Juan de Nova lagoon were submitted to a single exposure of diuron or naphthalene in triplicate outdoor 40-L mesocosms for 5 days. The study followed the temporal changes of the assemblages by determining abundances and taxonomic level of microbial (heterotrophic prokaryotes, picocyanobacteria, heterotrophic protists and phytoplankton) and metazooplankton communities. Exposure to both contaminants did not result in significant changes in phytoplankton abundances. Microscopic identification demonstrated the dominance of Bacillariophyta (mostly Chaetoceros tenuissimus) accounting for more than 95% of the microalgae detected in all mesocosms. Using 18S rRNA metabarcoding, temporal changes in the proportion of eukaryotic operational...
Tipo: Text
Palavras-chave: Contaminant; Taxonomy; Metabarcoding; Plankton; Experiments; Lagoon.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00681/79348/81853.pdf

Use of OmpU porins for attachment and invasion of Crassostrea gigas immune cells by the oyster pathogen Vibrio splendidus
Provedor de dados: 5
Autores: Duperthuy, Marylise; Schmitt, Paulina; Garzon, Edwin; Caro, Audrey; Rosa, Rafael D.; Le Roux, Frederique; Lautredou-audouy, Nicole; Got, Patrice; Romestand, Bernard; De Lorgeril, Julien; Kieffer-jaquinod, Sylvie; Bachere, Evelyne; Destoumieux-garzon, Delphine.
OmpU porins are increasingly recognized as key determinants of pathogenic host Vibrio interactions. Although mechanisms remain incompletely understood, various species, including the human pathogen Vibrio cholera, require OmpU for host colonization and virulence. We have shown previously that OmpU is essential for virulence in the oyster pathogen Vibrio splendidus LGP32. Here, we showed that V. splendidus LGP32 invades the oyster immune cells, the hemocytes, through subversion of host-cell actin cytoskeleton. In this process, OmpU serves as an adhesin/invasin required for beta-integrin recognition and host cell invasion. Furthermore, the major protein of oyster plasma, the extracellular superoxide dismutase Cg-EcSOD, is used as an opsonin mediating the...
Tipo: Text
Palavras-chave: Host-pathogen interaction; Innate immunity; Invertebrate; Mollusk; Oxidative burst.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14177/12166.pdf

Microbial food web structural and functional responses to oyster and fish as top predators
Provedor de dados: 5
Autores: Mostajir, Behzad; Roques, Cecile; Bouvier, Corinne; Bouvier, Thierry; Fouilland, Eric; Got, Patrice; Le Floc'H, Emilie; Nouguier, Jean; Mas, Sebastien; Sempere, Richard; Sime-ngando, Telesphore; Troussellier, Marc; Vidussi, Francesca.
The impact of fish and oysters on components of the pelagic microbial food web (MFW) was studied in a 10 d mesocosm experiment using Mediterranean coastal waters. Two mesocosms contained natural water only ('Controls'), 2 contained natural water with Crassostrea gigas ('Oyster'), and 2 contained natural water with Atherina spp. ('Fish'). Abundances and biomasses of microorganisms (viruses, bacteria, phytoplankton, heterotrophic flagellates, and ciliates) were measured to estimate their contribution to the total microbial carbon biomass. Two MFW indices, the microbial autotroph: heterotroph C biomass ratio (A:H) structural index and the gross primary production: respiration ratio (GPP:R) functional index, were defined. In the Fish mesocosms, selective...
Tipo: Text
Palavras-chave: Microbial food web; Virioplankton; Bacterioplankton; Phytoplankton; Protozooplankton; Crassostrea; Atherina; Autotrophy; Heterotrophy.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00284/39489/73675.pdf

Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field
Provedor de dados: 5
Autores: De Lorgeril, Julien; Escoubas, Jean Michel; Loubiere, Vincent; Pernet, Fabrice; Le Gall, Patrik; Vergnes, Agnes; Aujoulat, Fabien; Jeannot, Jean-luc; Jumas-bilak, Estelle; Got, Patrice; Gueguen, Yannick; Destoumieux-garzon, Delphine; Bachere, Evelyne.
Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We...
Tipo: Text
Palavras-chave: Host pathogen interaction; Innate immunity; Invertebrate; Mollusk; In situ mortality; Total bacteria; Crassostrea gigas.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00433/54470/55845.pdf

Spatiotemporal variations in microbial diversity across the three domains of life in a tropical thalassohaline lake (Dziani Dzaha, Mayotte Island)
Provedor de dados: 5
Autores: Hugoni, Mylene; Escalas, Arthur; Bernard, Cecile; Nicolas, Sebastien; Jezequel, Didier; Vazzoler, Fanny; Sarazin, Gerard; Leboulanger, Christophe; Bouvy, Marc; Got, Patrice; Ader, Magali; Troussellier, Marc; Agogue, Helene.
Thalassohaline ecosystems are hypersaline environments originating from seawater in which sodium chloride is the most abundant salt and the pH is alkaline. Studies focusing on microbial diversity in thalassohaline lakes are still scarce compared with those on athalassohaline lakes such as soda lakes that have no marine origin. In this work, we investigated multiple facets of bacterial, archaeal and eukaryotic diversity in the thalassohaline Lake Dziani Dzaha using a metabarcoding approach. We showed that bacterial and archaeal diversity were mainly affected by contrasting physicochemical conditions retrieved at different depths. While photosynthetic microorganisms were dominant in surface layers, chemotrophic phyla (Firmicutes or Bacteroidetes) and...
Tipo: Text
Palavras-chave: Archaea; Bacteria; Eukaryotes; Extreme environment; Metabarcoding; Thalassohaline lake.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00464/57564/59738.pdf