title: Temporal dynamics and phylogenetic diversity of free-living and particle-associated Verrucomicrobia communities in relation to environmental variables in a mesotrophic lake.
abstract: In the present study, the abundance and phylogenetic diversity of free-living and particle-associated Verrucomicrobia were investigated in a mesotrophic lake by quantitative PCR and sequencing of the 16S rRNA gene. The relative verrucomicrobial 16S rRNA gene abundance accounted for 0.02% to 1.98% of the particle-associated bacteria and 0.52% to 1.64% of the free-living bacteria. In total, 71 operational taxonomic units (OTUs) (n = 303 clones) were identified for particle-associated bacteria, and 59 OTUs (n = 292 clones) were identified for the free-living fraction. This study determined six new putative freshwater Verrucomicrobia clusters. Of these newly defined clusters, two were exclusively represented by particle-associated bacteria (FukuS27, BourFIV). The freshwater Verrucomicrobia clusters CRE-PA29, FukuN18 and CL120-10 appeared to be dominant, comprising 22.3%, 16.15% and 14.61% of the total retrieved OTUs, respectively. The seasonal dynamics of phytoplankton communities resulted in changes in the distinct bacterial phylotypes for both the particle-associated and free-living verrucomicrobial communities. According to canonical correspondence analysis, the diversity of the particle-associated verrucomicrobial communities appeared to be primarily influenced by phytoplankton richness, rotifer abundance and inorganic nutrients, whereas the free-living fraction was correlated with the biomass dynamics of some phytoplankton classes (Chlorophyceae, Chrysophaceae, Desmidiaceae and Zygnemataceae).
authors.affiliation: Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes: Génome et Environnement, BP 10448, Clermont-Ferrand, France.
authors.forename: Bushra
authors.initials: B
authors.lastname: Parveen
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mary
authors.forename: Agnès
authors.initials: A
authors.lastname: Vellet
authors.forename: Viviane
authors.initials: V
authors.lastname: Ravet
authors.forename: Didier
authors.initials: D
authors.lastname: Debroas
mesh_terms: D044822:Biodiversity; D018533:Biomass; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005618:Fresh Water / Q000382:microbiology; D005798:Genes, Bacterial; D060106:Lakes / Q000382:microbiology*; D010802:Phylogeny; D010839:Phytoplankton / Q000254:growth & development; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D061327:Verrucomicrobia / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S