Abstract EANA2024-114

The astonishing capability of life to adapt to extreme conditions provides a new perspective on what habitable’ means. Desert cyanobacteria of the genus Chroococcidiopsis have been used in several laboratory simulations of space and planetary conditions as well in real space exposure and Martian simulations in low Earth orbit. So far experiments were performed on dried cells and analysis were performed after the sample retrieval back to Earth.When exposure conditions did not exceed the repair capabilities, insights were gained on the constraints that life can withstand, whereas when the accumulated damage exceeded the survival potential, the biomarker persistence contributed to the search for life. Results of the Biology and Mars Experiment (BIOMEX) and Biofilm Organisms Surfing Space (BOSS) space missions, performed outside the International Space Station, showed that ultraviolet radiation is the main factor affecting survival and biomarkers detectability. On the contrary, high doses of ionizing radiation did not impair biomarker detectability both when detecting Raman spectra, or fluorescent signals in immunoassay, as tested in the context of the Bio-Signatures and habitable Niches (BIOSIGN) by using the Signs of Life Detector (SOLID)-LDChip system. It is now needed to expose hydrated desert cyanobacteria to non-Earth conditions and monitor their survival and cellular responses. It is also needed to further expand the limit of life as we know on Earth by boosting the survival potential of desert cyanobacteria by using a synthetic biology approach. These are the main challenges that will be faced in the context of the ASTERIA (Adaptability of cyanobacteria from extreme environments to stellar UV radiation) project funded by ASI. In particular, desert strains of Chroococcidiopsis capable of harvesting near-infrared, a phenomenon known as far-red light photoacclimation, will be used as model system to expand the knowledge the limit of oxygenic photosynthesis under non-Earth conditions focusing un UV radiation. The possibility of real-time monitoring of cyanoabcterial response to DNA-damaging conditions is under investigation in context of the ALCYONE (Autonomous Living Cell analYsis ON-chip for Evaluation of space Environment Effects) project funded by EU. In  particular a genetic system based on biolumiscence is under development for a desert strain of Chroococcidiopsis. Results will lay the foundations towards future experiments beyond low Earth orbit.