7th joint conference "Joint Microbiology & Infection Conference 2024" of the DGHM and VAAM

Abstract: Introduction: The search for life on Mars involves understanding the habitability of its surface and near subsurface, particularly in relation to the presence of salts and their solutions, such as perchlorates (ClO4-), which were detected on the Red Planet but are rare on Earth. Studies of our research group aim to investigate the microbiological responses to Martian-relevant salts, focusing on their tolerances and stress reactions.
Goals: The primary objectives included determining the salt tolerances of various halophilic and halotolerant microorganisms, assessing their survivability under Mars-like conditions, and analyzing their stress responses.
Materials & Methods: Microorganisms, including model species and environmental isolates, were subjected to varying concentrations of sodium perchlorate (NaClO4) and other salts to assess their tolerances. Mars-like environmental conditions were simulated in a chamber, and survival rates in Martian regolith mixed with different salts were measured. Salt stress responses were analyzed using microscopic, proteomic, and metabolomic techniques.
Results: Most halotolerant organisms exhibited higher NaClO4 tolerances than obligatory halophiles, suggesting their adaptability to habitat-untypical salts. The halotolerant yeast Debaryomyces hansenii demonstrated the highest tolerance, leading to further investigations. Chlorates (ClO3-) were tolerated in significantly higher concentrations than perchlorates, suggesting an increased habitability potential for chlorate-rich areas on Mars. Proteomic analyses revealed perchlorate-specific stress responses, particularly in D. hansenii, indicating chaotropic stress as a significant factor.
Summary: Experiments in Mars-simulated conditions showed that Martian subsurface may offer a more hospitable environment than the surface, with chlorates enhancing habitability over perchlorates. Microbial stress responses to perchlorate, analyzed through morphological, proteomic, and metabolomic approaches, highlighted species-specific reactions, emphasizing the necessity of understanding adaptations to Martian conditions for future astrobiological research.


Jacob Heinz

Invited Speaker