title: Anaerobic microbial communities in Lake Pavin, a unique meromictic lake in France.
abstract: The Bacteria and Archaea from the meromictic Lake Pavin were analyzed in samples collected along a vertical profile in the anoxic monimolimnion and were compared to those in samples from the oxic mixolimnion. Nine targeted 16S rRNA oligonucleotide probes were used to assess the distribution of Bacteria and Archaea and to investigate the in situ occurrence of sulfate-reducing bacteria and methane-producing Archaea involved in the terminal steps of the anaerobic degradation of organic material. The diversity of the complex microbial communities was assessed from the 16S rRNA polymorphisms present in terminal restriction fragment (TRF) depth patterns. The densities of the microbial community increased in the anoxic layer, and Archaea detected with probe ARCH915 represented the largest microbial group in the water column, with a mean Archaea/Eubacteria ratio of 1.5. Terminal restriction fragment length polymorphism (TRFLP) analysis revealed an elevated archaeal and bacterial phylotype richness in anoxic bottom-water samples. The structure of the Archaea community remained rather homogeneous, while TRFLP patterns for the eubacterial community revealed a heterogeneous distribution of eubacterial TRFs.
authors.affiliation: Laboratoire de Biologie des Protistes, UMR CNRS 6023, 24 avenue des Landais, 63177 Aubière Cedex, France. A-Catherine.LEHOURS@univ-bpclermont.fr
authors.forename: Anne-C
authors.initials: AC
authors.lastname: Lehours
authors.forename: Corinne
authors.initials: C
authors.lastname: Bardot
authors.forename: Aurelie
authors.initials: A
authors.lastname: Thenot
authors.forename: Didier
authors.initials: D
authors.lastname: Debroas
authors.forename: Gerard
authors.initials: G
authors.lastname: Fonty
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D019641:DNA, Archaeal / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis; D017753:Ecosystem; D005602:France; D005618:Fresh Water / Q000382:microbiology*; D008697:Methane / Q000378:metabolism; D015345:Oligonucleotide Probes / Q000235:genetics; D010100:Oxygen / Q000494:pharmacology; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016999:Sulfur-Reducing Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D015345:Oligonucleotide Probes; D012336:RNA, Ribosomal, 16S; D008697:Methane; D010100:Oxygen