Stratification of Archaea in the Deep Sediments of a Freshwater Meromictic Lake: Vertical Shift from Methanogenic to Uncultured Archaeal Lineages
journal contributionposted on 2013-11-22, 00:00 authored by Guillaume Borrel, Anne-Catherine Lehours, Olivier Crouzet, Didier Jezequel, Karl Rockne, Amelie Kulczak, Emilie Duffaud, Keith Joblin, Gerard Fonty
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.
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.
Publisher Statement© 2012 Borrel et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PublisherPublic Library of Science