Stratification of Archaea in the deep sediments of a freshwater meromictic lake: vertical shift from methanogenic to uncultured archaeal lineages

PLoS One. 2012;7(8):e43346. doi: 10.1371/journal.pone.0043346. Epub 2012 Aug 21.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaea / classification
  • Archaea / genetics*
  • Archaea / metabolism*
  • DNA, Archaeal / genetics
  • DNA, Ribosomal / genetics
  • Geologic Sediments* / chemistry
  • Geologic Sediments* / microbiology
  • Lakes* / chemistry
  • Lakes* / microbiology
  • Methane / biosynthesis*
  • Oxygen / analysis
  • Polymerase Chain Reaction
  • RNA, Archaeal / genetics
  • RNA, Ribosomal, 16S / genetics

Substances

  • DNA, Archaeal
  • DNA, Ribosomal
  • RNA, Archaeal
  • RNA, Ribosomal, 16S
  • Methane
  • Oxygen

Grants and funding

This work was funded by the Programme EC2CO of the French Centre National de la Recherche Scientifique (Projects Methanolac and Interlac). The work was also supported by a grant to GB from the region Auvergne. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.