Woods Hole Oceanographic Institution

»Bioavailability of soil organic matter and microbial community dynamics upon permafrost thaw
»7000 years of virus-host molecular dynamics in the Black Sea
»Preservation potential of ancient DNA in Pleistocene marine sediments: Implications for paleoenvironmental reconstructions
»Source-specific variability in post-depositional DNA preservation with potential implications for DNA-based paleecological records
»Exploring preserved ancient dinoflagellalte and haptophyte DNA signatures to infer ecological and environmental conditions during sapropel S1 formation in the eastern Mediterranean
»Ancient DNA in lake sediment records
»Vertical distribution of metabolically active eukaryotes in the water column and sediments of the Black Sea
»DNA and lipid molecular stratigraphic records of haptophyte succession in the Black Sea during the Holocene
»Diversity of Archaea and potential for crenarchaeotal nitrification of group 1.1a in the rivers Rhine and TĂȘt
»Holocene sources of fossil BHPs
»An unusual 17[α],21[β](H)-bacteriohopanetetrol in Holocene sediments from Ace Lake (Antarctica)
»Holocene sources of organic matter in Antarctic fjord
»Variations in spatial and temporal distribution of Archaea in the North Sea
»Archaeal nitrifiers in the Black Sea
»Pleistocene Mediterranean sapropel DNA
»Rapid sulfurisation of highly branched isoprenoid (HBI) alkenes in sulfidic Holocene sediments
»Aerobic and anaerobic methanotrophs in the Black Sea water column
»Fossil DNA in Cretaceous Black Shales: Myth or Reality?
»Sulfur and methane cycling during the Holocene in Ace Lake (Antarctica)
»Ancient algal DNA in the Black Sea
»Archaeal nitrification in the ocean
»Characterization of microbial communities found in the human vagina by analysis of terminal restriction fragment length polymorphisms of 16S rRNA genes
»Biomarker and 16S rDNA evidence for anaerobic oxidation of methane and related carbonate precipitation in deep-sea mud volcanoes of the Sorokin Trough, Black Sea
»Temperature-dependent variation in the distribution of tetraether membrane lipids of marine Crenarchaeota: Implications for TEX86 paleothermometry
»Paleoecology of algae in Ace Lake
»Evolution of the methane cycle in Ace Lake (Antarctica) during the Holocene: Response of methanogens and methanotrophs to environmental change
»Ongoing modification of Mediterranean Pleistocene sapropels mediated by prokaryotes.
»Microbial communities in the chemocline of a hypersaline deep-sea basin (Urania basin, Mediterranean Sea)
»Functional exoenzymes as indicators of metabolically active bacteria in 124,000-year-old sapropel layers of the Eastern Mediterranean Sea
»Specific detection of different phylogenetic groups of chemocline bacteria based on PCR and denaturing gradient gel electrophoresis of 16S rRNA gene fragments
»Analysis of subfossil molecular remains of purple sulfur bacteria in a lake sediment
»Effects of nitrate availability and the presence of Glyceria maxima the composition and activity of the dissimilatory nitrate-reducing bacterial community
»Microbial activities and populations in upper sediment and sapropel layers

Coolen, M. J. L., G. Muyzer, S. Schouten, J. K. Volkman and J. S. Sinninghe Damsté, Sulfur and methane cycling during the Holocene in Ace Lake (Antarctica) revealed by lipid and DNA stratigraphy, in Past and Present Marine Water Column Anoxia, NATO Science Series: IV-Earth and Environmental Sciences, edited by L. N. Neretin, pp. 41-65, Springer, Dordrecht, 2006

Postglacial Ace Lake (Vestfold Hills, Antarctica) was initially a freshwater lake, then an open marine system, and finally the present-day saline, stratified basin with anoxic, sulfidic, and methane-saturated bottom waters. Stratigraphic analysis of carotenoids and ancient 16S rDNA in sediment cores revealed that almost immediately after marine waters entered the palaeo freshwater lake as a result of post-glacial sea-level rise, Ace Lake became meromictic with the formation of sul.dic bottom waters and a chemocline colonized by obligate anoxygenic photolithotrophic green sulfur bacteria (Chlorobiaceae). Ancient 16S rDNA stratigraphy revealed that the fossil source of chlorobactene throughout the Holocene as well as in the present-day chemocline of Ace Lake was a species with 99.6% sequence similarity to the 16S rDNA sequence of Chlorobium phaeovibrioides DSMZ 269T. Comparison of the ratio between rDNA and chlorobactene of the latter species in the water column and in Holocene sediment layers revealed that the degradation of DNA was mostly influenced by the preservation conditions of the ancient water column. Within the sulfidic Holocene sediments, the remaining ancient DNA of green sulfur bacteria was more stable than intact carotenoids. We showed the development of anoxygenic photosynthesis with our previous stratigraphic analysis of 16S rDNA and lipid biomarkers indicative for prokaryotes involved in the cycling of methane in order to get a more complete picture of anoxygenic processes in Ace Lake during the Holocene. Full text is available here.

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