Digital Commons Network^™

Predominant Archaea In Marine Sediments Degrade Detrital Proteins, Karen Lloyd, Lars Schreiber, Dorthe G. Petersen, Kasper U. Kjeldsen, Mark A. Lever, Andrew D. Steen, Ramunus Stepanauskas, Michael Richter, Sara Kleindienst, Sabine Lenk, Andreas Schramm, Bo Barker Jørgensen

Karen Lloyd

Half of the microbial cells in the Earth’s oceans are found in sediments. Many of these cells are members of the Archaea, singlecelled prokaryotes in a domain of life separate from Bacteria and Eukaryota. However, most of these archaea lack cultured representatives, leaving their physiologies and placement on the tree of life uncertain. Here we show that the uncultured miscellaneous crenarchaeotal group (MCG) and marine benthic group-D (MBG-D) are among the most numerous archaea in the marine sub-sea floor. Single-cell genomic sequencing of one cell of MCG and three cells of MBG-D indicated that they form new branches basal to …