title: Structural Diversity of Bacterial Communities Associated with Bloom-Forming Freshwater Cyanobacteria Differs According to the Cyanobacterial Genus.
abstract: The factors and processes driving cyanobacterial blooms in eutrophic freshwater ecosystems have been extensively studied in the past decade. A growing number of these studies concern the direct or indirect interactions between cyanobacteria and heterotrophic bacteria. The presence of bacteria that are directly attached or immediately adjacent to cyanobacterial cells suggests that intense nutrient exchanges occur between these microorganisms. In order to determine if there is a specific association between cyanobacteria and bacteria, we compared the bacterial community composition during two cyanobacteria blooms of Anabaena (filamentous and N2-fixing) and Microcystis (colonial and non-N2 fixing) that occurred successively within the same lake. Using high-throughput sequencing, we revealed a clear distinction between associated and free-living communities and between cyanobacterial genera. The interactions between cyanobacteria and bacteria appeared to be based on dissolved organic matter degradation and on N recycling, both for N2-fixing and non N2-fixing cyanobacteria. Thus, the genus and potentially the species of cyanobacteria and its metabolic capacities appeared to select for the bacterial community in the phycosphere.
authors.affiliation: iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France.
authors.forename: Imen
authors.initials: I
authors.lastname: Louati
authors.affiliation: iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Pascault
authors.affiliation: Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Clermont Université Blaise Pascal, Aubière, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Debroas
authors.affiliation: MCAM MNHN, UMR CNRS 7245, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Bernard
authors.affiliation: iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Humbert
authors.affiliation: iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Leloup
mesh_terms: D017033:Anabaena / Q000145:classification / Q000235:genetics*; D044822:Biodiversity; D017753:Ecosystem; D005068:Eutrophication; D005618:Fresh Water; D059014:High-Throughput Nucleotide Sequencing; D046931:Microcystis / Q000145:classification / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation; D010802:Phylogeny; D010839:Phytoplankton / Q000145:classification / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*
chemical_list: D012336:RNA, Ribosomal, 16S; D009584:Nitrogen