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Microbial Lipid and C Isotopic Biosignatures of a Unique Community at Grand Prismatic Spring, Yellowstone National ParkThe microbial communities found in modern hot springs are considered analogs to ones that may have existed in hydrothermal systems on the early Earth and possibly Mars. Our goal was to characterize the microbial biosignatures and to assess the preservation of organic matter in the silica-depositing Grand Prismatic Spring in Yellowstone National Park. This study combines 16S rRNA surveys, lipid biomarkers, and C isotopes to query, "Who's there and what are they doing?" On the edge of the approximately 90 m diameter blue vent pool (56.1 C, pH 8.5), a floating green streamer community grew over a benthic pink community. The membrane lipids in the green streamers and pink mat were composed of unusual ester-linked fatty acids, indicating the presence of novel bacterial groups. In particular, we discovered a series of 2-methyl and 2,X-dimethyl phospholipid fatty acids (C18-22). We are attempting to use the 16S rRNA surveys to link these compounds to source organisms. Wax esters, biomarkers for Chloroflexi, were present in both communities, but displayed different profiles. A higher proportion of branched wax esters were found in the green streamers, and were associated with a relatively high concentration of long-chain di- and trienes (C29-31). This suggests that Chloroflexus primarily grew in the green streamers, while a pink mat of Roseiflexus grew on the sinter substrate underneath. Cyanobacterial alkanes were found in the green streamers (n-C17, 7-, 6- and 5-monomethyl-C17, 7,11-dimethyl-C17, n-C19, n-C19:1). We also detected a series of monoalkylglycerylethers and geologically relevant hopanoids in both communities. Carbon isotope analyses indicated that Chloroflexus was growing photoheterotrophically using cyanobacterial photosynthate. Roseiflexus also traditionally grows photoheterotrophically, but the C isotopic signatures of the lipids in the pink mat were approximately 10 %0 lighter than the cyanobacterial and Chloroflexus lipids, indicating a potentially novel metabolic mechanism or prior secondary reworking of substrates before reaching Roseiflexus. This arrangement of Synechococcus-Chloroflexus green streamers floating over a benthic pink community of Roseiflexus is different from the classical laminated Synechococcus-Chloroflexi mats at Octopus Hot Spring.
Document ID
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Jahnke, Linda
(NASA Ames Research Center Moffett Field, CA, United States)
Parenteau, Mary
(Search for Extraterrestrial Intelligence Inst. Moffett Field, CA, United States)
Farmer, Jack
(Arizona State Univ. Tempe, AZ, United States)
Date Acquired
August 27, 2013
Publication Date
June 18, 2012
Subject Category
Report/Patent Number
Meeting Information
Meeting: 112th General Meeting American Society for Microbiology (ASM) 2012
Location: San Francisco, CA
Country: United States
Start Date: June 16, 2012
End Date: June 19, 2012
Sponsors: American Society for Microbiology
Funding Number(s)
WBS: WBS 811073.
Distribution Limits
Public Use Permitted.
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