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Auteur Trottet, A.; Leboulanger, C.; Vidussi, F.; Pete, R.; Bouvy, M.; Fouilland, E. url  doi
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  Titre Heterotrophic Bacteria Show Weak Competition for Nitrogen in Mediterranean Coastal Waters (Thau Lagoon) in Autumn Type Article scientifique
  Année 2016 Publication Revue Abrégée Microb Ecol  
  Volume (down) 71 Numéro 2 Pages 304-314  
  Mots-Clés Bacteria; Dissolved inorganic nitrogen; Ecology; Geoecology/Natural Processes; Inhibitors; Microbial ecology; Microbiology; Nature Conservation; Nitrogen uptake; Phytoplankton; Size fractionation; Water Quality/Water Pollution  
  Résumé The importance of heterotrophic bacteria relative to phytoplankton in the uptake of ammonium and nitrate was studied in Mediterranean coastal waters (Thau Lagoon) during autumn, when the Mediterranean Sea received the greatest allochthonous nutrient loads. Specific inhibitors and size-fractionation methods were used in combination with isotopic 15N tracers. NO3 − and NH4 + uptake was dominated by phytoplankton (60 % on average) during the study period, which included a flood event. Despite lower biomass specific NH4 + and NO3 uptake rates, free-living heterotrophic bacteria contributed significantly (>30 %) to total microbial NH4 + and NO3 − uptake rates in low chlorophyll waters. Under these conditions, heterotrophic bacteria may be responsible for more than 50 % of primary production, using very little freshly produced phytoplankton exudates. In low chlorophyll coastal waters as reported during the present 3-month study, the heterotrophic bacteria seemed to depend to a greater extent on allochthonous N and C substrates than on autochthonous substrates derived from phytoplankton.  
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  ISSN 0095-3628, 1432-184x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1448  
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Auteur Amossé, J.; Bettarel, Y.; Bouvier, C.; Bouvier, T.; Tran Duc, T.; Doan Thu, T.; Jouquet, P. url  doi
openurl 
  Titre The flows of nitrogen, bacteria and viruses from the soil to water compartments are influenced by earthworm activity and organic fertilization (compost vs. vermicompost) Type Article scientifique
  Année 2013 Publication Revue Abrégée Soil Biology & Biochemistry  
  Volume (down) 66 Numéro Pages 197-203  
  Mots-Clés Bacterial and viral abundance; Bacterial diversity; Compost; Dichogaster bolaui; Earthworms; Leaching; Organic fertilization; Vermicompost  
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  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0038-0717 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 892  
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Auteur Bouvy, M.; Combe, M.; Bettarel, Y.; Dupuy, C.; Rochelle-Newall, E.; Charpy, L. url  doi
openurl 
  Titre Uncoupled viral and bacterial distributions in coral reef waters of Tuamotu Archipelago (French Polynesia) Type Article scientifique
  Année 2012 Publication Revue Abrégée Marine Pollution Bulletin  
  Volume (down) 65 Numéro 10–12 Pages 506-515  
  Mots-Clés Coral reef waters; Distributions; Strategy lifes; Virus; bacteria  
  Résumé This study examined the distribution of virioplankton and bacterioplankton in two coral reef systems (Ahe and Takaroa atolls) in the Tuamotu Archipelago, in comparison with the surrounding oligotrophic ocean. Mean concentrations of 4.8 × 105 and 6.2 × 105 cells ml−1 for bacteria and 8.1 × 106 and 4.3 × 106 VLP (virus-like particle) ml−1 were recorded in Ahe and Takaroa lagoons, respectively. Chlorophyll-a concentrations and dissolved organic matter were higher in Ahe whereas 3H thymidine incorporation rates were higher in Takaroa. First data on lytic and lysogenic strategies of phages in coral reef environments were discussed in this paper. The fraction of visibly infected cells by viruses was negligible regardless of the lagoon station (mean = 0.15%). However, the fraction of lysogenic cells ranged between 2.5% and 88.9%. Our results suggest that the distribution patterns of virioplankton are apparently not coupled to the spatial dynamics of the bacterioplankton communities.  
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  ISSN 0025-326x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 923  
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Auteur Boukef, I.; Bejaoui, B.; Hassan, M.B.; Mraouna, R.; Got, P.; Harzallah, A.; Elbour, M. url  openurl
  Titre Spatial distribution and decay rates of coliforms in the sediments and water column of the bizerte lagoon Type Article scientifique
  Année 2012 Publication Revue Abrégée Vie Milieu  
  Volume (down) 62 Numéro 1 Pages 29-36  
  Mots-Clés bizerte lagoon; coastal waters; contamination; environmental-conditions; escherichia coli decay; estuarine; fecal indicator bacteria; pathogenic bacteria; pollution; recreational waters; seasonal survey; seawater; sunlight; sunlight inactivation; total coliform  
  Résumé In order to assess the impact of bacterial input loads in Bizerte lagoon (Northern Tunisia), a seasonal survey was done for total coliform bacteria covering the whole lagoon area, to reproduce and prevent dispersion of input loads of terrestrial discharges in the lagoon. Effect of solar radiation on Escherichia coli strains was investigated using seawater microcosms comparatively exposed to sunlight and dark conditions. The results revealed (i) high charges of coliforms in the sediment rather than in the water column, (ii) total coliforms increased periodically with season in both compartments, (iii) anthropogenic discharges influence coastal areas of the lagoon, and (iv) solar radiation has an effect on decay rate of E. coli maintained in microcosm experiments.  
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  Langue English Langue du Résumé Titre Original  
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  ISSN 0240-8759 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 846  
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Auteur Auguet, J.C.; Montanie, H.; Hartmann, H.J.; Lebaron, P.; Casamayor, E.O.; Catala, P.; Delmas, D. doi  openurl
  Titre Potential effect of freshwater virus on the structure and activity of bacterial communities in the Marennes-Oleron Bay (France) Type Article scientifique
  Année 2009 Publication Revue Abrégée Microb Ecol  
  Volume (down) 57 Numéro 2 Pages 295-306  
  Mots-Clés 16S/genetics Seasons Seawater/microbiology/virology Viruses/*growth & development *Water Microbiology; Bacteria/genetics/*growth & development/*virology Biodiversity Colony Count; Bacterial/genetics France Fresh Water/virology Polymorphism; Microbial DNA Fingerprinting DNA; Ribosomal; Single-Stranded Conformational Population Dynamics RNA  
  Résumé Batch culture experiments using viral enrichment were conducted to test the response of a coastal bacterial community to autochthonous (i.e., co-existing) or allochthonous riverine viruses. The effects of viral infections on bacterial dynamics and activity were assessed by epifluorescence microscopy and thymidine incorporation, respectively, whereas the effect of viral infection on bacterial community composition was examined by polymerase chain reaction-single strand conformation polymorphism 16S ribosomal RNA fingerprinting. The percentages of high nucleic acid-containing cells, evaluated by flow cytometry, were significantly correlated (r2=0.91, n=12, p<0.0001) to bacterial production, making this value a good predictor of active cell dynamics along the study. While confinement and temperature were the two principal experimental factors affecting bacterial community composition and dynamics, respectively, additions of freshwater viruses had significant effects on coastal bacterial communities. Thus, foreign viruses significantly reduced net bacterial population increase as compared to the enrichment treated with inactivated virus. Moreover, freshwater viruses recurrently and specifically affected bacterial community composition, as compared to addition of autochthonous viruses. In most cases, the combined treatment viruses and freshwater dissolved organic matter helped to maintain or even enhance species richness in coastal bacterial communities in agreement to the 'killing the winner' hypothesis. Thus, riverine virus input could potentially influence bacterial community composition of the coastal bay albeit with modest modification of bulk bacterial growth.  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1301  
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