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Auteur Meistertzheim, A.-L.; Lartaud, F.; Arnaud-Haond, S.; Kalenitchenko, D.; Bessalam, M.; Le Bris, N.; Galand, P.E.
Titre Patterns of bacteria-host associations suggest different ecological strategies between two reef building cold-water coral species Type Article scientifique
Année 2016 Publication Revue Abrégée Deep Sea Research Part I: Oceanographic Research Papers
Volume 114 Numéro Pages 12-22
Mots-Clés Bacterial communities; Bacterial ecology; Deep-Sea corals; Lophelia pertusa; Madrepora oculata; Mediterranean Sea; Microbe-microbe and microbe-host interactions
Résumé Cold-water corals (CWC) are main ecosystem engineers of the deep sea, and their reefs constitute hot-spots of biodiversity. However, their ecology remains poorly understood, particularly, the nature of the holobiont formed by corals with their associated bacterial communities. Here, we analyzed Madrepora oculata and Lophelia pertusa samples, collected from one location in a Mediterranean canyon in two different seasons (autumn and spring), in order to test for species specificity and temporal stability of the host-bacteria associations. The 16S rRNA sequencing revealed host-specific patterns of bacterial communities associated with L. pertusa and M. oculata, both in terms of community composition and diversity. All analyzed M. oculata polyps exhibited temporally and spatially similar bacterial communities dominated by haplotypes homologous to the known cnidarians-associated genus Endozoicomonas. In contrast, the bacterial communities associated with L. pertusa varied among polyps from the same colony, as well as among distinct colonies and between seasons. While the resilient consortium formed by M. oculata and its bacterial community fit the definition of holobiont, the versatility of the L. pertusa microbiome suggests that this association is more influenced by the environmental conditions or nutritional status. Our results thus highlight distinct host/microbes association strategies for these two closely related Scleractinians sharing the same habitat, suggesting distinct sensitivity to environmental change.
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ISSN 0967-0637 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1565
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Auteur Nguyen-Kim, H.; Bouvier, T.; Bouvier, C.; Bui, V.N.; Le-Lan, H.; Bettarel, Y.
Titre Viral and Bacterial Epibionts in Thermally-Stressed Corals Type Article scientifique
Année 2015 Publication Revue Abrégée Journal of Marine Science and Engineering
Volume 3 Numéro 4 Pages 1272-1286
Mots-Clés Bacteria; coral bleaching; holobiont; thermal stress; Vietnam; viruses
Résumé The periodic rise in seawater temperature is one of the main environmental determinants of coral bleaching. However, the direct incidence of these episodic thermal anomalies on coral-associated microbiota and their subsequent effects on coral health are still not completely understood. In this study, we investigated the dynamics of three main microbial communities of the coral holobiont (e.g., Symbiodinium, bacteria and viruses), during an experimental thermal stress (+4 °C) conducted on the scleractinian Fungia repanda. The heat-treatment induced coral bleaching after 11 days and resulted in a final elevation of ca. 9, 130 and 250-fold in the abundance of mucosal viruses, bacteria, and Symbiodinium, respectively. On the contrary, the proportion of actively respiring bacterial cells declined by 95% in heat-stressed corals. The community composition of epibiotic bacteria in healthy corals also greatly differed from bleached ones, which also exhibited much higher production rates of viral epibionts. Overall, our results suggest that the shift in temperature induced a series of microbial changes, including the expulsion and transfer of Symbiodinium cells from the coral polyps to the mucus, the collapse of the physiological state of the native bacterial associates, a substantial alteration in their community structure, and accompanied by the development of a cortege of highly active virulent phages. Finally, this study provides new insights into the environmentally-driven microbial and viral processes responsible for the dislocation of the coral holobiont.
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Numéro d'Appel MARBEC @ alain.herve @ collection 1478
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Auteur Nguyen-Kim, H.; Bouvier, T.; Bouvier, C.; Hai, D.N.; Lam, N.N.; Rochelle-Newall, E.; Baudoux, A.C.; Desnues, C.; Reynaud, S.; Ferrier-Pages, C.; Bettarel, Y.
Titre High occurrence of viruses in the mucus layer of scleractinian corals Type Article scientifique
Année 2014 Publication Revue Abrégée Environmental Microbiology Reports
Volume 6 Numéro 6 Pages 675-682
Mots-Clés abundance; bacteria; communities; diversity; ecology; gradient gel-electrophoresis; level physiological profiles; microbial; reef; release; water
Résumé Viruses attract increasing interest from environmental microbiologists seeking to understand their function and role in coral health. However, little is known about their main ecological traits within the coral holobiont. In this study, a quantitative and qualitative characterization of viral and bacterial communities was conducted on the mucus of seven different coral species of the Van Phong Bay (Vietnam). On average, the concentrations of viruses and bacteria were, respectively, 17- and twofold higher in the mucus than in the surrounding water. The examination of bacterial community composition also showed remarkable differences between mucus and water samples. The percentage of active respiring cells was nearly threefold higher in mucus (m=24.8%) than in water (m=8.6%). Interestingly, a positive and highly significant correlation was observed between the proportion of active cells and viral abundance in the mucus, suggesting that the metabolism of the bacterial associates is probably a strong determinant of the distribution of viruses within the coral holobiont. Overall, coral mucus, given its unique physicochemical characteristics and sticking properties, can be regarded as a highly selective biotope for abundant, diversified and specialized symbiotic microbial and viral organisms.
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ISSN 1758-2229 ISBN Médium
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Notes <p>ISI Document Delivery No.: AU6GU<br/>Times Cited: 1<br/>Cited Reference Count: 51<br/>Nguyen-Kim, Hanh Bouvier, Thierry Bouvier, Corinne Hai Doan-Nhu Lam Nguyen-Ngoc Rochelle-Newall, Emma Baudoux, Anne-Claire Desnues, Christelle Reynaud, Stephanie Ferrier-Pages, Christine Bettarel, Yvan<br/>EC2CO CORINE Project; TOTAL Foundation; French Institute of Research for Development (IRD)<br/>This work was supported by the EC2CO CORINE Project, the TOTAL Foundation and the French Institute of Research for Development (IRD). We thank Telesphore Sime-Ngando, Didier Debroas, Pham The Thu, Chu Van Thuoc, Sonia Monteil and Delphine Bonnet for their participation in the CORINE mission in Vietnam, their assistance in diving, field operations and technical support during the cruise, and Sebastien Villeger for his advice on statistical analysis. We are also very grateful to Michel Galey, Alexandre Portier and all the staff from Whale Island Resort for their hospitality and help during our stay.<br/>Wiley-blackwell<br/>Hoboken</p> Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1170
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Auteur Pereira, O.; Hochart, C.; Auguet, J.C.; Debroas, D.; Galand, P.E.
Titre Genomic ecology of Marine Group II, the most common marine planktonic Archaea across the surface ocean Type Article scientifique
Année 2019 Publication Revue Abrégée MicrobiologyOpen
Volume 8 Numéro 9 Pages e852
Mots-Clés 16S rRNA; abundance; assemblages; bacteria; carbon; community; dynamics; euryarchaeota; Euryarchaeota; global ocean; insights; metagenomics; organisms; poseidoniales; proteorhodopsin
Résumé Planktonic Archaea have been detected in all the world's oceans and are found from surface waters to the deep sea. The two most common Archaea phyla are Thaumarchaeota and Euryarchaeota. Euryarchaeota are generally more common in surface waters, but very little is known about their ecology and their potential metabolisms. In this study, we explore the genomic ecology of the Marine Group II (MGII), the main marine planktonic Euryarchaeota, and test if it is composed of different ecologically relevant units. We re-analyzed Tara Oceans metagenomes from the photic layer and the deep ocean by annotating sequences against a custom MGII database and by mapping gene co-occurrences. Our data provide a global view of the distribution of Euryarchaeota, and more specifically of MGII subgroups, and reveal their association to a number of gene-coding sequences. In particular, we show that MGII proteorhodopsins were detected in both the surface and the deep chlorophyll maximum layer and that different clusters of these light harvesting proteins were present. Our approach helped describing the set of genes found together with specific MGII subgroups. We could thus define genomic environments that could theoretically describe ecologically meaningful units and the ecological niche that they occupy.
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ISSN 2045-8827 ISBN Médium
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Notes WOS:000485975100029 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2653
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Auteur Pringault, O.; Lafabrie, C.; Avezac, M.; Bancon-Montigny, C.; Carré, C.; Chalghaf, M.; Delpoux, S.; Duvivier, A.; Elbaz-Poulichet, F.; Gonzalez, C.; Got, P.; Leboulanger, C.; Spinelli, S.; Hlaili, A.S.; Bouvy, M.
Titre Consequences of contaminant mixture on the dynamics and functional diversity of bacterioplankton in a southwestern Mediterranean coastal ecosystem Type Article scientifique
Année 2016 Publication Revue Abrégée Chemosphere
Volume 144 Numéro Pages 1060-1073
Mots-Clés aquatic systems; Bacterial growth efficiency; Bacterial production; bizerte lagoon; Community level physiological profiles; growth efficiency; Herbicides; heterotrophic bacteria; Metals; microbial communities; Microcosms; organic-carbon; polycyclic aromatic-hydrocarbons; sediment resuspension; substrate utilization pattern; surface sediments
Résumé Contamination of coastal environments is often due to a complex mixture of pollutants, sometimes in trace levels, that may have significant effects on diversity and function of organisms. The aim of this study was to evaluate the short-term dynamics of bacterioplankton exposed to natural and artificial mixtures of contaminants. Bacterial communities from a southwestern Mediterranean ecosystem, lagoon and the bay (offshore) of Bizerte were exposed to i) elutriate from resuspension of contaminated sediment, and ii) an artificial mixture of metals and herbicides mimicking the contamination observed during sediment resuspension. Elutriate incubation as well as artificial spiking induced strong enrichments in nutrients (up to 18 times), metals (up to six times) and herbicides (up to 20 times) relative to the in situ concentrations in the offshore station, whereas the increases in contaminants were less marked in the lagoon station. In the offshore waters, the artificial mixture of pollutants provoked a strong inhibition of bacterial abundance, production and respiration and significant modifications of the potential functional diversity of bacterioplankton with a strong decrease of the carbohydrate utilization. In contrast, incubation with elutriate resulted in a stimulation of bacterial activities and abundances, suggesting that the toxic effects of pollutants were modified by the increase in nutrient and DOM concentrations due to the sediment resuspension. The effects of elutriate and the artificial mixture of pollutants on bacterial dynamics and the functional diversity were less marked in the lagoon waters, than in offshore waters, suggesting a relative tolerance of lagoon bacteria against contaminants. (C) 2015 Elsevier Ltd. All rights reserved.
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ISSN 0045-6535 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1507
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