Lipid Biomarker Record of the Serpentinite-Hosted Ecosystem of the Samail Ophiolite, Oman and Implications for the Search for Biosignatures on Mars

Sharon A. Newman, Sara A. Lincoln, Shane O'Reilly, Xiaolei Liu, Everett L. Shock, Peter B. Kelemen, Roger E. Summons

Research output: Contribution to journalArticlepeer-review

Abstract

Serpentinization is a weathering process in which ultramafic rocks react with water, generating a range of products, including serpentine and other minerals, in addition to H2 and low-molecular-weight hydrocarbons that are capable of sustaining microbial life. Lipid biomarker analyses of serpentinite-hosted ecosystems hold promise as tools for investigating microbial activity in ancient Earth environments and other terrestrial planets such as Mars because lipids have the potential for longer term preservation relative to DNA, proteins, and other more labile organic molecules. Here, we report the first lipid biomarker record of microbial activity in the mantle section of the Samail Ophiolite, in the Sultanate of Oman, a site undergoing active serpentinization. We detected isoprenoidal (archaeal) and branched (bacterial) glycerol dialkyl glycerol tetraether (GDGT) lipids, including those with 0-3 cyclopentane moieties, and crenarchaeol, an isoprenoidal GDGT containing four cyclopentane and one cyclohexane moieties, as well as monoether lipids and fatty acids indicative of sulfate-reducing bacteria. Comparison of our geochemical data and 16S rRNA data from the Samail Ophiolite with those from other serpentinite-hosted sites identifies the existence of a common core serpentinization microbiome. In light of these findings, we also discuss the preservation potential of serpentinite lipid biomarker assemblages on Earth and Mars. Continuing investigations of the Samail Ophiolite and other terrestrial analogues will enhance our understanding of microbial habitability and diversity in serpentinite-hosted environments on Earth and elsewhere in the Solar System.

Original languageEnglish (US)
Pages (from-to)830-845
Number of pages16
JournalAstrobiology
Volume20
Issue number7
DOIs
StatePublished - Jul 1 2020

Keywords

  • Biosignatures - Mars.
  • Lipid biomarkers - Ophiolite - Serpentinization

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Lipid Biomarker Record of the Serpentinite-Hosted Ecosystem of the Samail Ophiolite, Oman and Implications for the Search for Biosignatures on Mars'. Together they form a unique fingerprint.

Cite this