HR: 16:00h
AN: B14A-01 INVITED     [Abstracts]
TI: Molecular Studies of Filamentous and Biofilm-Forming Hyperthermophilic Communities in Yellowstone National Park
AU: * Summons, R E
EM: rsummons@mit.edu
AF: Dept. Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Meyer-Dombard, D R
EM: drmd@mit.edu
AF: Dept. Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Bradley, A S
EM: bradleya@mit.edu
AF: Dept. Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Dibbell, A K
EM: gusgus@mit.edu
AF: Dept. Earth, Atmospheric and Planetary Sciences Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Fredricks, H F
EM: hfredricks@whoi.edu
AF: Woods Hole Oceanographic Institution, Woods Hole Road, Woods Hole, MA 02543 United States
AU: Hinrichs, K
EM: khinrichs@uni-bremen.de
AF: RCOM & Dept. of Geosciences,University of Bremen, PO Box 330 440, Bremen, D-28334 Germany
AU: Jahnke, L L
EM: Linda.L.Jahnke@nasa.gov
AF: Exobiology Branch, NASA, Ames Research Center, Moffett Field, CA 94035 United States
AU: Shock, E
EM: eshock@asu.edu
AF: Dept. of Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85287-140 United States
AU: Amend, J P
EM: amend@levee.wustl.edu
AF: Dept. of Earth and Planetary Sciences, Washington University, 1 Brookings Drive, St. Louis, MO 63130 United States
AB: The Aquificales, the most deeply-branching order of Bacteria in the phylogenetic tree of life, comprises eight recognized thermophilic genera, including Aquifex, Hydrogenobacter, and Thermocrinis. The common metabolism for these Bacteria, when grown in culture, is the oxidation of hydrogen with molecular oxygen (Knallgas reaction). Aquificales have been identified by molecular techniques (16S rRNA gene surveys, fluorescent in situ hybridization) in Yellowstone National Park (YNP), sea vent chimneys and fluids, and many other terrestrial and marine locations. In situ, Aquificales can reside as biofilms on vent sinters but they also commonly form filamentous communities, otherwise known as pink streamers, which attach to solid substrates. Initial 16S rRNA gene surveys conducted on streamer communities from Octopus Spring YNP indicated that these were low diversity ecosystems dominated by a few phylotypes including Thermocrinis sp., Thermotoga sp. and one other bacterial clade (Reysenbach et al 1994). Archaea were notable for their absence. In one of the first geobiological studies of pink streamers and vent biofilms in Yellowstone National Park, Jahnke and coworkers (2001) used classical lipidological techniques to compare Aquificales cultures with environmental samples to show that YNP pink filaments were more phylogenetically diverse and physiologically more complex than the early genomic studies indicated. The presence of archaeol, the range and structures of other lipids and a wide dispersion in the carbon isotopic signatures of biomass and individual lipids (-15 to -27%) showed that Archaea were present in pink filament communities and that there was, at least, one additional bacterial group besides the dominant Aquificales component. New molecular studies that comprise analyses of 16S rRNA genes and total lipid extracts by liquid chromatography and mass spectrometry and chemical degradation with gas chromatography and mass spectrometry now show that Crenarchaea are a quantitatively important component of the pink streamer communities. Moreover, the streamer distribution has an overt provinciality suggesting control by hydrogen availability, or some other geochemical factor that remains to be determined. Our combined analyses of genomes and intact polar lipids will add significantly to the growing bank of data on the geochemical signatures and broad environmental distributions of Crenarchaea.
DE: 0400 BIOGEOSCIENCES
DE: 0410 Biodiversity
DE: 0419 Biomineralization
DE: 0424 Biosignatures and proxies
DE: 0456 Life in extreme environments
SC: Biogeosciences [B]
MN: Fall Meeting 2005