Lipid biomarkers reveal metabolic heterogeneity in Antarctic cryptoendolithic communities: implications for astrobiology - Research data

We investigate lipid biomarkers (linear and branched hydrocarbons, n-alkanols, sterols, saturated and unsaturated fatty acids) in cryptoendolithic communities inhabiting Beacon Supergroup sandstones collected from four sites in Victoria Land, Antarctica. Total lipid extracts were obtained by accelerated solvent extraction, fractionated, and analyzed by GC-MS. Despite low total organic carbon contents, different lipid patterns were detected. Battleship Promontory and Linnaeus Terrace showed higher abundances of short-chain n-alkanes, n-alkenes, unsaturated fatty acids, ergosterol, and PUFAs, consistent with relatively active or recently active microbial communities and reflecting diverse environmental conditions. Overall, results demonstrate that lipid biomarkers can capture both recent biological activity and long-term molecular preservation in Antarctic cryptoendolithic systems and act as robust indicators of microbial habitability and biosignature preservation in extraterrestrial analog environments. Timber Peak exhibited lipid patterns indicative of transitional or mummified communities, whereas Mt. Fleming was characterized by lower organic carbon, scarce unsaturated compounds, and a predominance of stable saturated lipids, suggesting highly degraded or fossilized microbial remains.