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Auteur Pringault, O.; Viret, H.; Duran, R. url  doi
  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.  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0944-1344 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 683  
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