Can bacteria survive under the harsh conditions of Mars?
Study with bacteria under Martian conditions
Focus: Space travel
Can bacteria survive under the harsh conditions of Mars?
PhD student Tommaso Zaccaria at the DLR Institute of Aerospace Medicine has been investigating this topic with environment-derived opportunistic bacterial pathogens exposed to Martian simulated conditions. This project, a collaboration between DLR and Radboud University Medical Center had the aim of evaluating the survival of four bacterial species to Martian simulated conditions, with the results being published on the scientific journal Astrobiology Vol. 24(1). Tommaso made use of the DLR’s planetary simulation facilities at the Institute of Aerospace Medicine to expose the bacteria.
In the paper titled “Survival of Environment-Derived Opportunistic Bacterial Pathogens to Martian Conditions: Is There a Concern for Human Missions to Mars?” Tommaso (DLR Astrobiology research group of the Radiation Biology department) and collaborators show the survival extent of Burkholderia cepacia, Pseudomonas aeruginosa, Serratia marcescens and Klebsiella pneumoniae. The bacteria were grown in minimal media conditions and exposed to the Mars extreme conditions such as desiccation, ultraviolet C and polychromatic ultraviolet radiation, growth in combination with perchlorate salts (identified by rovers on Mars and which can make up brines or be present where liquid water could be) and a Mars regolith simulant (MGS-1, Exolith Lab) as well as Mars atmosphere and pressure.
This study not only highlights the importance of spacecraft decontamination measures but also the implications for a human mission to Mars. As the species investigated can be part of the human gut microbiome, it is likely that they will be unwillingly carried on a space mission to the red planet. That organisms have been carried to space has been proven by in previous studies on the ISS and during other space missions showing the presence of diverse microorganisms, including bacteria, fungi and archaea. Furthermore, it is important to highlight that the human immune system is dysregulated in space, and it can therefore be suggested that an infection with pathogenic bacteria could pose a stronger challenge during space missions than on Earth.
The DLR and Radboud UMC collaboration is continuing, with the groups currently investigating the response of human immune cells, specifically mononuclear cells from peripheral blood (PBMCs), via cell signaling molecules called cytokines, to the bacteria that have been exposed to the simulated Mars conditions. This investigation helps to understand the immune response towards bacteria which survived Mars conditions. This understanding is crucial to safeguard the health of astronauts during missions to the red planet.
