title: Bacterial community composition characterization of a lead-contaminated Microcoleus sp. consortium.
abstract: BACKGROUND
  A Microcoleus sp. consortium, obtained from the Ebro delta microbial mat, was maintained under different conditions including uncontaminated, lead-contaminated, and acidic conditions.
  
  
  METHODS
  Terminal restriction fragment length polymorphism and 16S rRNA gene library analyses were performed in order to determine the effect of lead and culture conditions on the Microcoleus sp. consortium.
  
  
  RESULTS
  The bacterial composition inside the consortium revealed low diversity and the presence of specific terminal-restriction fragments under lead conditions. 16S rRNA gene library analyses showed that members of the consortium were affiliated to the Alpha, Beta, and Gammaproteobacteria and Cyanobacteria. Sequences closely related to Achromobacter spp., Alcaligenes faecalis, and Thiobacillus species were exclusively found under lead conditions while sequences related to Geitlerinema sp., a cyanobacterium belonging to the Oscillatoriales, were not found in presence of lead.
  
  
  CONCLUSIONS
  This result showed a strong lead selection of the bacterial members present in the Microcoleus sp. consortium. Several of the 16S rRNA sequences were affiliated to nitrogen-fixing microorganisms including members of the Rhizobiaceae and the Sphingomonadaceae. Additionally, confocal laser scanning microscopy and scanning and transmission electron microscopy showed that under lead-contaminated condition Microcoleus sp. cells were grouped and the number of electrodense intracytoplasmic inclusions was increased.
authors.affiliation: UFR Sciences et Techniques, Equipe Environnement et Microbiologie-UMR IPREM5254, Université de Pau et des Pays de l'Adour, Avenue de l'Université, Pau Cedex, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Giloteaux
authors.forename: Antoni
authors.initials: A
authors.lastname: Solé
authors.forename: Isabel
authors.initials: I
authors.lastname: Esteve
authors.forename: Robert
authors.initials: R
authors.lastname: Duran
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D000458:Cyanobacteria / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D015723:Gene Library; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000633:toxicity*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D012336:RNA, Ribosomal, 16S / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D007854:Lead