A hidden pattern? Common polyextremophilic microbial adaptations in Icy Moon analog environments

The search for life signatures beyond Earth is one of the main objectives of space exploration. Studies of analogous terrestrial ecosystems have shed light on the limits of life and on the adaptations of microbial communities to thrive in these extreme environments resembling Icy Moons. However, their findings tend to be compartmentalized, which hinders the drawing of broad conclusions about the drivers and challenges for life. This study aims to identify general characteristics of microbial communities inhabiting terrestrial analogs of Icy Moons, applying a novel meta-analysis on publicly available 16S rRNA amplicon sequencing data. We also seek to apply our findings to a new fundamental approach in the search for life in Europa and Enceladus, locations where life may exist. Our results suggest that depth, pH and hypersalinity are the key environmental drivers for microbial taxa distribution and molecular adaptations, with halophilic archaea showing ubiquitous presence. Integrating diverse datasets into a single meta-analysis allowed us to infer statistically significant microbial patterns related to adaptation to the Icy Moons' analog conditions, notably that osmolytes and modified lipids emerged as a shared adaptive strategy, regardless of depth. Our findings are aimed to helping guide future life detection efforts in these extraterrestrial environments.