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Abstract EANA2024-51


Adaptation Mechanisms of Microorganisms to Martian Salts

Jacob Heinz (1), and the BRINES team (2)
(1) Research Group Astrobiology, Center for Astronomy and Astrophysics, Technische Universität Berlin, Germany, (2) Including all students (Camilo Mayr-Wolf, Florian Carlo Fischer, Elisa Soler, Anne Gries, Shivani Nundoo, Lea Kloss, Weronika Julia Lukas, Vita Rambags, Ksenia Malahov) involved in the DFG project “BRINES” (#455070607), and the research group leader Dirk Schulze-Makuch


Investigating putative life on Mars requires a thorough understanding of the planet's habitability, particularly regarding the presence of salts such as perchlorates, which are abundant on Mars but rare on Earth. Our research focuses on how microorganisms respond to Mars-relevant salts, specifically their tolerance levels and stress responses.

Our study aimed to determine the salt tolerance of various halophilic and halotolerant microorganisms, evaluate their survivability under Mars-like conditions, and investigate their stress responses to these salts. We subjected both model organisms and environmental isolates to various concentrations of sodium perchlorate and other salts to gauge their tolerance levels. We employed microscopic, proteomic, and metabolomic techniques to analyze the organisms' stress responses.

Halotolerant microorganisms displayed higher tolerance to sodium perchlorate compared to obligatory halophiles, indicating their adaptability to atypical salts. The halotolerant yeast Debaryomyces hansenii showed the highest tolerance, prompting more detailed investigations. Chlorates were tolerated at significantly higher concentrations than perchlorates, indicating that chlorate-rich regions on Mars might offer increased habitability. Proteomic analysis of D. hansenii revealed specific stress responses to perchlorates such as cell wall remodulations and protein glycosylation, highlighting chaotropic (i.e. biomacromolecule-destabilizing) stress as a critical factor.

Comparisons of microbial stress responses of different organisms to salts occurring on Mars revealed species-specific adaptation mechanisms that showed only a low degree of overlap, indicating diverse evolutionary pathways for coping with salts other than NaCl. These findings underscore the importance of understanding microbial adaptations to Martian conditions for advancing astrobiological research.