||Roussel Erwan1, Sauvadet Anne-Laure1, Chaduteau Carine2, Fouquet Yves2, Charlou Jean-Luc2, Prieur Daniel1, Cambon Marie-Anne1
||1 : Univ Bretagne Occidentale, CNRS, Inst Univ Europeen Mer, Lab Microbiol Environm Extremes,UMR 6197,Ifremer, F-29280 Plouzane, France.
2 : IFREMER, Ctr Brest, Dept Geosci Marines, F-29280 Plouzane, France.
||Environmental Microbiology (1462-2912) (Wiley / Blackwell), 2009-09 , Vol. 11 , N. 9 , P. 2446-2462
|WOS© Times Cited
||marine subsurface sediments, sea floor biosphere, gradient gel electrophoresis, microbial communities, molecular diversity, anaerobic oxidation, sequence alignment, phylogenetic trees, extracellular DNA, methane hydrate
||P>The distribution of the archaeal communities in deep subseafloor sediments [0-36 m below the seafloor (mbsf)] from the New Caledonia and Fairway Basins was investigated using DNA- and RNA-derived 16S rRNA clone libraries, functional genes and denaturing gradient gel electrophoresis (DGGE). A new method, Co-Migration DGGE (CM-DGGE), was developed to access selectively the active archaeal diversity. Prokaryotic cell abundances at the open-ocean sites were on average similar to 3.5 times lower than at a site under terrestrial influence. The sediment surface archaeal community (0-1.5 mbsf) was characterized by active Marine Group 1 (MG-1) Archaea that co-occurred with ammonia monooxygenase gene (amoA) sequences affiliated to a group of uncultured sedimentary Crenarchaeota. However, the anoxic subsurface methane-poor sediments (below 1.5 mbsf) were dominated by less active archaeal communities, such as the Thermoplasmatales, Marine Benthic Group D and other lineages probably involved in the methane cycle (Methanosarcinales, ANME-2 and DSAG/MBG-B). Moreover, the archaeal diversity of some sediment layers was restricted to only one lineage (Uncultured Euryarchaeota, DHVE6, MBG-B, MG-1 and SAGMEG). Sequences forming two clusters within the Thermococcales order were also present in these cold subseafloor sediments, suggesting that these uncultured putative thermophilic archaeal communities might have originated from a different environment. This study shows a transition between surface and subsurface sediment archaeal communities.