20-EPN2-069: Challenging the adaptability of an anhydrobiotic cyanobacterium to Mars-like conditions
Visit by Beatriz Gallego Fernandez, University of Rome Tor Vergata (Italy), to TA2 Facility 6 – DLR Planetary Simulation Laboratory (PASLAB) (Germany).
Dates of visit: 21-29 July 2022
Report Summary: Different studies reported the endurance of cyanobacteria to Mars-like conditions; however, little is known about the cellular and molecular mechanisms responsible for this resistance. The further combination of Martian UV fluxes and perchlorate ions at concentrations found on the surface of Mars increases the challenges for survival. Under this context, this study aimed to investigate the adaptability and cellular responses of metabolically active biofilms of Chroococcidiopsis CCMEE 029 to Martian surface-like conditions combined with perchlorate ions.
Biofilms obtained from cells mixed with two different Martian regolith analogs and 2.4 mM of perchlorate ions on top of an agarized regolith-based medium were exposed to unprotected Mars-like conditions for 3 days. Parameters consisted of a Mars-like atmosphere (95% CO2, 4% N2, 1% O2) constant pressure of 700 Pa, periodic photosynthetically active radiation (PAR, 400-700nm, 3W/ m²/s) and UV (4W/m²/s) irradiation for 16 h followed by 8 h of dark with diurnal cycling of relative humidity and temperature from 75% to 0% and +15ºC to -50ºC respectively. The photosynthetic yield was followed during the exposure with the Mini-PAM analyzer integrated into the Martian simulation chamber. Post-exposure analyses of cell-viability assessment, CFU capacity, and pigment autofluorescence and morphology will be performed. Proteomics analyses are ongoing in collaboration with Dr. Peter Lasch from the Robert Koch Institute, Berlin (Doellinger et al. 2020).
Overall, this study will contribute to extending our appreciation of the limits of life as we know it, from the habitability of Mars to future management of Life Support and In-Situ Resource Utilization systems.
Read the full scientific report, with kind permission by Beatriz Gallego Fernández.