NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Linking Archaeal Molecular Diversity and Lipid Biomarker Composition in a Hypersaline Microbial Mat CommunityLipid biomarkers for discrete microbial groups are a valuable tool for establishing links to ancient microbial ecosystems. Lipid biomarkers can establish organism source and function in contemporary microbial ecosystems (membrane lipids) and by analogy, potential relevance to the fossilized carbon skeletons (geolipids) extracted from ancient sedimentary rock. The Mars Exploration Rovers have provided clear evidence for an early wet Mars and the presence of hypersaline evaporitic basins. Ongoing work on an early Earth analog, the hypersaline benthic mats in Guerrero Negro, Baja California Sur, may provide clues to what may have evolved and flourished on an early wet Mars, if only for a short period. Cyanobacterial mats are a pertinent early Earth analog for consideration of evolutionary and microbial processes within the aerobic photosynthetic and adjacent anoxic layers. Fluctuations in physio-chemical parameters associated with spatial and temporal scales are expressed through vast microbial metabolic diversity. Our recent work hopes to establish the dynamic of archaeal diversity, particularly as it relates to methane production in this high sulfate environment, through the use of lipid biomarker and phylogenetic analyses. Archaeal 16s rRNA and mcrA gene assemblages, demonstrated distinct spatial separation over the 130 mm core of at least three distinct genera within the order Methanosarcinales, as well as an abundance of uncultured members of the Thermoplasmales and Crenarchaeota. Ether-bound lipid analysis identified abundant 0-alkyl and 0-isopranyl chains throughout the core, and the presence of sn-2 hydroxyarchaeol, a biomarker for methylotrophic methanogens. A unique ether isoprenoid chain, a C30:1 , possibly related to the geolipid squalane, a paleobiomarker associated with hypersaline environments, was most abundant within the oxic-anoxic transition zone.
Document ID
20050180823
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Jahnke, Linda
(NASA Ames Research Center Moffett Field, CA, United States)
Orphan, Victoria
(California Inst. of Tech. Pasadena, CA, United States)
Turk, Kendra
(California Inst. of Tech. Pasadena, CA, United States)
Embaye, Tsegereda
(Search for Extraterrestrial Intelligence Inst. CA, United States)
Kubo, Mike
(Search for Extraterrestrial Intelligence Inst. CA, United States)
Summons, Roger
(Massachusetts Inst. of Tech. MA, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Lunar And Planetary Science And Exploration
Meeting Information
Meeting: NAI Biennial Meeting of the NASA Astrobiology Institute
Location: Boulder, CO
Country: United States
Start Date: April 10, 2005
End Date: April 14, 2005
Sponsors: NASA Headquarters
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available