title: Stratification of Archaea in the deep sediments of a freshwater meromictic lake: vertical shift from methanogenic to uncultured archaeal lineages.
abstract: As for lineages of known methanogens, several lineages of uncultured archaea were recurrently retrieved in freshwater sediments. However, knowledge is missing about how these lineages might be affected and structured according to depth. In the present study, the vertical changes of archaeal communities were characterized in the deep sediment of the freshwater meromictic Lake Pavin. For that purpose, an integrated molecular approach was performed to gain information on the structure, composition, abundance and vertical stratification of archaeal communities thriving in anoxic freshwater sediments along a gradient of sediments encompassing 130 years of sedimentation. Huge changes occurred in the structure and composition of archaeal assemblages along the sediment core. Methanogenic taxa (i.e. Methanosaeta and Methanomicrobiales) were progressively replaced by uncultured archaeal lineages (i.e. Marine Benthic Group-D (MBG-D) and Miscellaneous Crenarchaeal Group (MCG)) which are suspected to be involved in the methane cycle.
authors.affiliation: Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Clermont Université, Aubière, France. Guillaume.borrel@univ-bpclermont.fr
authors.forename: Guillaume
authors.initials: G
authors.lastname: Borrel
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Lehours
authors.forename: Olivier
authors.initials: O
authors.lastname: Crouzet
authors.forename: Didier
authors.initials: D
authors.lastname: Jézéquel
authors.forename: Karl
authors.initials: K
authors.lastname: Rockne
authors.forename: Amélie
authors.initials: A
authors.lastname: Kulczak
authors.forename: Emilie
authors.initials: E
authors.lastname: Duffaud
authors.forename: Keith
authors.initials: K
authors.lastname: Joblin
authors.forename: Gérard
authors.initials: G
authors.lastname: Fonty
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D019641:DNA, Archaeal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D060106:Lakes / Q000737:chemistry / Q000382:microbiology; D008697:Methane / Q000096:biosynthesis*; D010100:Oxygen / Q000032:analysis; D016133:Polymerase Chain Reaction; D019642:RNA, Archaeal / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D019641:DNA, Archaeal; D004275:DNA, Ribosomal; D019642:RNA, Archaeal; D012336:RNA, Ribosomal, 16S; D008697:Methane; D010100:Oxygen