Exploration of microbial-mineral interactions with the Noachian Martian breccia composed of ~4.5 Gyr old crustal materials from Mars

In the past year we have been witnessing several important missions to Mars, including Mars 2020 Perseverance rover that landed to Jezero Crater to search for signs of ancient life. Multiple lines of evidence indicate an active hydrogeological history of Mars and chemolithoautotrophy-suited environments within its Noachian terrains. As a result, one of the primary aims of Mars missions is to search for signs of ancient life and collect a suite of samples to be returned to Earth via a Mars Sample Return mission. Being a few steps away from retrieving and returning the first Mars samples, we need to gain extensive knowledge how to access their potential biogenicity. In this connection, a valuable source of information can be extracted from microbial fingerprints of chemolithotrophic life based on Martian materials. Chemolithoautotrophy is the most ancient microbial form of life, which enables the transition of energy from a stone to the energy of a living entity. In our project, we investigate interactions of a wide variety of chemolithoautotrophs with Martian mineral materials (Martian meteorites and regolith simulants). Our recent research on the genuine Noachian Martian breccia “Black Beauty” permitted visualization and nanometer-scale imaging of microbial life designed and cultivated on Martian materials(1). Here we report on laboratory-scaled microbially assisted chemolithoautotrophic biotransformation(1) of the Noachian Martian breccia Northwest Africa (NWA) 7034 composed of ancient (~4.5 Gyr old) crustal materials from Mars. Nanoanalytical hyperspectral analysis provides clues for the trafficking and distribution of meteorite inorganic constituents in the microbial cell(1). We decipher biomineralization patterns associated with the biotransformation and reveal microbial nanometer-sized lithologies located inside the cell and on its outer surface layer(1). These investigations provide an opportunity to trace the putative bioalteration processes of the Martian crust and to assess the potential biogenicity of Martian materials. Our study on the Noachian Martian breccia composed of ~4.5 Gyr old crustal materials from Mars, delivered a prototype of microbial life experimentally designed on a real Martian material(1). This life of a pure Martian design is a rich source of Mars relevant biosignatures.

 

1. Milojevic, T., Albu, M., Kölbl, D. et al. Chemolithotrophy on the Noachian Martian breccia NWA 7034 via experimental microbial biotransformation. Commun Earth Environ 2, 39 (2021). https://doi.org/10.1038/s43247-021-00105-x