Abstract_EANA2025-82

Abstract EANA2025-82

Viability evaluation of antarctic cryptoendolithic communities exposed to Mars simulated conditions.

DEL FRANCO C. (1) (CARMEN.DELFRANCO@UNITUS.IT), BELMONTE LOPES R. (1), PEZZILLI S. (2), PEDONE M.(2), BAQUÉ M. (3), LOREK A. (3), GARLAND S. (3), SELBMANN L. (1).

(1) Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy. (2) ASI- Italian Space Agency, Rome, Italy (3) German Aerospace Center (DLR), Institute of Space Research, Planetary Laboratories Department, Berlin, Germany.

The discovery of Earth-like planets in our galaxy (1) has made it possible to deepen our knowledge of the potential habitability of other planets in the solar system (2) and to identify the presence of environments that can be traced to the possibility of past and present life beyond Earth (3). Among these, Mars remains one of the main astrobiological targets (4). A modern approach involves the so-called "Planetary Field Analogues" (PFAs) to investigate this possibility by studying terrestrial life forms that can live in areas where environmental conditions are so extreme that they can be compared with extraterrestrial ones (5). The PFAs include the “Martian analogues on Earth” (2), the best of which are the ice-free areas of continental Antarctica (6). Here, life is only possible for specialised microbial species that colonise the interstices of porous rocks and adopt cryptoendolithism as a survival strategy (7). Thus, the Antarctic cryptoendolithic communities can be considered as a proxy to evaluate and understand if and how microbial species may have lived on Mars or Mars-like planets. The project CRYPTOMARS aims to evaluate the survival of these communities exposed to Mars-like stresses and to outline the characteristics of a putative microbial community capable of surviving on the Red Planet. A selection of cryptoendolithically colonised rock samples, collected in Battleship Promontory and Linnaeus Terrace (Southern Victoria Land, Antarctica), was exposed in the –Planetary Analogue Simulation Laboratory (PALAB) at DLR, Berlin (8) for 21 days. After treatment, samples were grinded into a fine powder and viability of the communities was evaluated applying different methods. A molecular approach was based on the Propidium MonoAzide (PMA) assay (9); this test allows to distinguish, and quantify by qPCR viable and non-viable cells, preventing the amplification of dead cells' DNA that PMA binds once penetrated their damaged membranes. In order to quantify the presence of metabolic activity in the communities, the Fluorescein diacetate (10) and ATP assay (11) were performed while, for the analysis of cultivable species, a culturomic approach was used by seeding samples on solid culture media (12).
The results of these tests give a clear picture of the survival capability of the communities of both sites and will be completed with a multi-omic characterization, which includes metagenomics, metabolomics and lipidomics.
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