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Auteur Doan, T.T.; Bouvier, C.; Bettarel, Y.; Bouvier, T.; Henry-des-Tureaux, T.; Janeau, J.L.; Lamballe, P.; Nguyen, B.V.; Jouquet, P. url  doi
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  Titre (up) Influence of buffalo manure, compost, vermicompost and biochar amendments on bacterial and viral communities in soil and adjacent aquatic systems Type Article scientifique
  Année 2014 Publication Revue Abrégée Applied Soil Ecology  
  Volume 73 Numéro Pages 78-86  
  Mots-Clés Mesocosms; Organic fertilization; Soil; Virus; bacteria; water  
  Résumé Vermicompost and biochar amendments are management practices which may contribute to sustainable agroecosystems by reducing dependence on inorganic fertilizers. However, little is known about their impacts on soil microorganisms and their transfer and evolution in connected aquatic systems. The aim of this study was to determine the influence of organic manure (buffalo manure, compost or vermicompost) and biochar amendments on bacterial and viral properties in soil and water. A three year experiment was carried out with terrestrial mesocosms which were used to test the effect of organic matter amendment on maize growth. In the last year of the experiment, runoff and infiltration waters from the terrestrial mesocosms were transferred to aquatic mesocosms. Organic fertilization improved soil properties (higher C, N content and pH H 2 O ) and as a consequence increased soil bacterial and viral abundance. Bacterial diversity (Shannon ‘H’ and richness ‘S’ indices calculated from DGGE fingerprint) was also enhanced after the continuous application of organic amendments. Compared with compost, vermicompost reduced viral abundance and S but similar H and bacterial abundance were observed. The pH H 2 O , C content and bacterial and viral abundance increased in the aquatic mesocosms following organic fertilization. As a consequence, bacterial and viral diversity also increased in the water, although no differences were found between compost and vermicompost. Biochar increased soil bacterial abundance for the mineral fertilizer treatment but did not influence bacterial and viral abundance in water. However, the combination of biochar and vermicompost led to an increase of viruses in soil and a reduction of bacteria in water. Similarity dendrograms from the DGGE banding patterns showed that the structure of bacterial communities was mainly influenced by the fertilizer treatments in soil but by the presence of biochar in water. In conclusion, this study demonstrated that the nature of the organic amendment has important consequences on both soil and water microbial abundance and diversity.  
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  Langue Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0929-1393 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 673  
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Auteur BLANCHETON, J.-P.; Attramadal, K.J.K.; MICHAUD, L.; ROQUE D'ORBCASTEL, E.; Vadstein, O. url  openurl
  Titre (up) Insight into bacterial population in aquaculture systems and its implication Type Article scientifique
  Année 2013 Publication Aquacultural Engineering Revue Abrégée  
  Volume 53 Numéro Pages 30-39  
  Mots-Clés Intensive systems; Water recirculation; Bacterial population; Microbial management; Fish health  
  Résumé The current onshore aquaculture trend is to develop large scale production of diversified fingerlings and very large units for fish ongrowing. This requires an industrial type of approach including quality assurance and minimization of failures in addition to management of bio-technical and economic aspects. Therefore, all the key biological mechanisms involved in Recirculating Aquaculture Systems (RAS) need to be better understood, especially those determining the development of bacterial populations and their interactions with fish. This review presents new knowledge on bacterial community compositions in various parts of RAS and on bacterial-fish interactions in RAS, which constitute essential tools for system management. (C) 2012 Elsevier B.V. All rights reserved.  
  Adresse Norwegian Univ Sci & Technol NTNU, Dept Biotechnol, Trondheim, Norway.  
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  Editeur Elsevier Sci Ltd Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0144-8609 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 24464 collection 1219  
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Auteur Pringault, O.; Viret, H.; Duran, R. url  doi
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  Titre (up) Interactions between Zn and bacteria in marine tropical coastal sediments Type Article scientifique
  Année 2012 Publication Revue Abrégée Environ. Sci. Pollut. Res.  
  Volume 19 Numéro 3 Pages 879-892  
  Mots-Clés Bacterial diversity; Metal spiking; Microcosms; New Caledonia; T-Rflp; baltic sea sediments; community; coral-reef lagoon; fragment-length-polymorphism; heavy-metals; hypersaline microbial mat; new-caledonia lagoon; polluted anoxic sediments; salins-de-giraud; south-west lagoon; tolerance pict  
  Résumé Purpose The main goals of this study were (1) to examine the effects of zinc on the microbial community structure of anthropogenically impacted sediments in a tropical coastal ecosystem and (2) to determine whether these microbial benthic communities may enhance the adsorption of zinc. Methods The interactions between zinc and bacteria in tropical sediments were studied in sediment microcosms amended with 2.5 mg L-1 of Zn in the water phase and incubated for 8 days under different environmental conditions, oxic/anoxic and glucose addition. At the end of incubation, microbial structure was assessed by molecular fingerprints (T-RFLP) analysis and Zn speciation in the sediment was determined by sequential extraction. Results In the three studied sediments, Zn spiking resulted in only slight changes in bacterial community structure. In contrast, the addition of low concentrations of glucose (5mM) strongly modified the bacterial community structure: <20% of similarity with the initial structure concomitant with a strong diminution of the specific richness. Overall, these results suggest that highly labile organic matter has a larger impact on microbial structure than heavy metal. These weak impacts of Zn on bacteria diversity might be partly explained by (1) the strong adsorption of Zn in the presence of bacteria and/or (2) the incorporation of Zn into a nonbioavailable fraction. Nevertheless, Zn spiking resulted in significant changes in nutrient cycles, suggesting that bacterial metabolisms were impacted by the heavy metal. This led to an increase in nutrient supplies to the water column, potentially enhancing eutrophication in a nutrient-limited, oligotrophic ecosystem.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0944-1344 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 683  
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Auteur Gérard, E.; De Goeyse, S.; Hugoni, M.; Agogué, H.; Richard, L.; Milesi, V.; Guyot, F.; Lecourt, L.; Borensztajn, S.; Joseph, M.-B.; Leclerc, T.; Sarazin, G.; Jézéquel, D.; Leboulanger, C.; Ader, M. url  doi
openurl 
  Titre (up) Key Role of Alphaproteobacteria and Cyanobacteria in the Formation of Stromatolites of Lake Dziani Dzaha (Mayotte, Western Indian Ocean) Type Article scientifique
  Année 2018 Publication Revue Abrégée Front. Microbiol.  
  Volume 9 Numéro Pages  
  Mots-Clés alkaline lake; anoxygenic photrophic bacteria; aragonite; Hydromagnesite; Mg-silicate; Pleurocapsales; Stromatolites  
  Résumé Lake Dziani Dzaha is a thalassohaline tropical crater lake located on the “Petite Terre” Island of Mayotte (Comoros archipelago, Western Indian Ocean). Stromatolites are actively growing in the shallow waters of the lake shores. These stromatolites are mainly composed of aragonite with lesser proportions of hydromagnesite, calcite, dolomite and phyllosilicates. They are morphologically and texturally diverse ranging from tabular covered by a cauliflower-like crust to columnar ones with a smooth surface. High-throughput sequencing of bacterial and archaeal 16S rRNA genes combined with confocal laser scanning microscopy (CLSM) analysis revealed that the microbial composition of the mats associated with the stromatolites was clearly distinct from that of the Arthrospira-dominated lake water. Unicellular-colonial Cyanobacteria belonging to the Xenococcus genus of the Pleurocapsales order were detected in the cauliflower crust mats, whereas filamentous Cyanobacteria belonging to the Leptolyngbia genus were found in the smooth surface mats. Observations using CLSM, scanning electronic microscopy (SEM) and Raman spectroscopy indicated that the cauliflower texture consists of laminations of aragonite, magnesium-silicate phase and hydromagnesite. The associated microbial mat, as confirmed by laser microdissection and whole-genome amplification (WGA), is composed of Pleurocapsales coated by abundant filamentous and coccoid Alphaproteobacteria. These phototrophic Alphaproteobacteria promote the precipitation of aragonite in which they become incrusted. In contrast, the Pleurocapsales are not calcifying but instead accumulate silicon and magnesium in their sheaths, which may be responsible for the formation of the Mg-silicate phase found in the cauliflower crust. We therefore propose that Pleurocapsales and Alphaproteobacteria are involved in the formation of two distinct mineral phases present in the cauliflower texture: Mg-silicate and aragonite, respectively. These results point out the role of phototrophic Alphaproteobacteria in the formation of stromatolites, which may open new perspective for the analysis of the fossil record.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 1664-302x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2360  
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Auteur Brauer, V.S.; Stomp, M.; Rosso, C.; van Beusekom, S.A.M.; Emmerich, B.; Stal, L.J.; Huisman, J. url  doi
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  Titre (up) Low temperature delays timing and enhances the cost of nitrogen fixation in the unicellular cyanobacterium Cyanothece Type Article scientifique
  Année 2013 Publication Revue Abrégée The ISME journal  
  Volume 7 Numéro 11 Pages 2105-2115  
  Mots-Clés climate change; day-night cycle; nitrogen fixation; nitrogenase; respiration; unicellular cyanobacteria  
  Résumé Marine nitrogen-fixing cyanobacteria are largely confined to the tropical and subtropical ocean. It has been argued that their global biogeographical distribution reflects the physiologically feasible temperature range at which they can perform nitrogen fixation. In this study we refine this line of argumentation for the globally important group of unicellular diazotrophic cyanobacteria, and pose the following two hypotheses: (i) nitrogen fixation is limited by nitrogenase activity at low temperature and by oxygen diffusion at high temperature, which is manifested by a shift from strong to weak temperature dependence of nitrogenase activity, and (ii) high respiration rates are required to maintain very low levels of oxygen for nitrogenase, which results in enhanced respiratory cost per molecule of fixed nitrogen at low temperature. We tested these hypotheses in laboratory experiments with the unicellular cyanobacterium Cyanothece sp. BG043511. In line with the first hypothesis, the specific growth rate increased strongly with temperature from 18 to 30 degrees C, but leveled off at higher temperature under nitrogen-fixing conditions. As predicted by the second hypothesis, the respiratory cost of nitrogen fixation and also the cellular C:N ratio rose sharply at temperatures below 21 degrees C. In addition, we found that low temperature caused a strong delay in the onset of the nocturnal nitrogenase activity, which shortened the remaining nighttime available for nitrogen fixation. Together, these results point at a lower temperature limit for unicellular nitrogen-fixing cyanobacteria, which offers an explanation for their (sub)tropical distribution and suggests expansion of their biogeographical range by global warming.  
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  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1751-7370 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 696  
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