Protection Of Chemolithoautotrophic Bacteria Exposed To Simulated Mars Environmental Conditions

Felipe Gómez (1) , Eva Mateo-Martí (1) , Olga Prieto-Ballesteros (1) , Jose Martín-Gago (1) , Ricardo Amils (1, 2)

1 CAB - Centro de Astrobiologia [Madrid]
2 UAM - Universidad Autónoma de Madrid

Current surface conditions (strong oxidative atmosphere, UV radiation, low temperatures and xeric conditions) on Mars are considered extremely challenging for life. The question is whether there are any features on Mars that could exert a protective effect against the sterilizing conditions detected on its surface. Potential habitability in the subsurface would increase if the overlaying material played a protective role. With the aim of evaluating this possibility we studied the viability of two microorganisms under different conditions in a Mars simulation chamber. An acidophilic chemolithotroph isolated from Río Tinto belonging to the genus and , a radiation resistant microorganism, were exposed to simulated Mars conditions under the protection of a layer of ferric oxides and hydroxides, a Mars regolith analogue. Samples of these microorganisms were exposed to UV radiation in Mars atmospheric conditions at different time intervals under the protection of 2 and 5 mm layers of oxidized iron minerals. Viability was evaluated by inoculation on fresh media and characterization of their growth cultures. Here we report the survival capability of both bacteria to simulated Mars environmental conditions.

Mots clés: Mars; Astrobiology; Regoliths; Acidophilic bacteria; Planetary atmospheres simulation chamber

Domaines: Planète et Univers [physics]

Felipe Gómez, Eva Mateo-Martí, Olga Prieto-Ballesteros, Jose Martín-Gago, Ricardo Amils. Protection Of Chemolithoautotrophic Bacteria Exposed To Simulated Mars Environmental Conditions. Icarus, 2010, 209 (2), pp.482. ⟨10.1016/j.icarus.2010.05.027⟩. ⟨hal-00676214⟩