title: Seasonal and diel distributions of denitrifying and bacterial communities in a hypersaline microbial mat (Camargue, France).
abstract: Changes in spatio-temporal distribution of bacterial and denitrifying communities were qualitatively studied in a microbial mat from Camargue (France). During a diel and a seasonal cycle, patterns of 16S rRNA and nitrite reductase genes (nirS and nirK) were compared by denaturing gradient gel electrophoresis (DGGE). Statistical analysis of DGGE profiles showed a significant seasonal shift in the community structure of the nirS-containing bacteria with a winter superficial population that extended in summer, whereas the nirK-containing bacteria seemed more affected by vertical gradients rather than by month-to month-changes. Denitrifying activities remained stable during these sampling times. The bacterial community at the surface of the mat also changed according to season, but appeared stable over a day. Finally, during a diel cycle nirK populations were localized in zones with large fluctuations of environmental parameters (oxygen, pH, and sulfur levels) while nirS populations seemed more restricted to the permanent anoxic layer of the microbial mat.
authors.affiliation: Laboratoire de Microbiologie, de Géochimie et d'Ecologie Marines, CNRS-UMR 6117, Centre d'Océanologie de Marseille, Campus de Luminy, Case 901, 13288 Marseille cedex 9, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Desnues
authors.forename: Valérie D
authors.initials: VD
authors.lastname: Michotey
authors.forename: Andrea
authors.initials: A
authors.lastname: Wieland
authors.forename: Cui
authors.initials: C
authors.lastname: Zhizang
authors.forename: Aude
authors.initials: A
authors.lastname: Fourçans
authors.forename: Robert
authors.initials: R
authors.lastname: Duran
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Bonin
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D018441:Biofilms; D004591:Electrophoresis, Polyacrylamide Gel; D005602:France; D005798:Genes, Bacterial / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D012623:Seawater; D012965:Sodium Chloride
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D009584:Nitrogen