Vulnerable microbial communities in Atacama-Altiplano wetlands: modern analogs of ancient ecosystems with...

The Altiplano-Puna plateau lies at ∼4000 m above sea level in the volcanic Andes cordillera. Together with the adjacent Atacama Desert, it forms one of the most hyperarid regions on the planet. Wetlands are rare, influenced by hydrothermalism and, due to high evaporation rates, dominated by saline lakes and ephemeral ponds associated with salt flats (collectively called salares). Long thought to be lifeless, these environments host microbial ecosystems adapted to extreme conditions in terms of temperature, pH, salinity, ultraviolet radiation, and high concentrations of metals and metalloids, including arsenic, copper, and lithium. Climate change and mining activities, notably lithium extraction for "green energies," are causing the desiccation of these systems. Their microbial biodiversity risks being lost before it is studied. In this review, we highlight three major active research areas that provide added value to Atacama-Altiplano microbiomes beyond their intrinsic ecosystemic importance, identifying knowledge gaps and future research trends at the fundamental-applied science interface. First, studying these poorly known microbes may help us understand and exploit molecular adaptations to extreme conditions and better define the limits of life, with implications for astrobiology. Second, Atacama-Altiplano phototrophic microbial mats and microbialites can be suitable geochemical and biological analogs of ancient microbial ecosystems and reveal ecological and evolutionary aspects of paleoenvironments. Third, these microbial ecosystems represent an untapped reservoir of robust enzymes for biocatalysis, as well as environmentally friendly solutions for sustainable copper and lithium mining, recycling, and bioremediation processes. Collectively, these arguments justify the urgency of prioritizing these unique microbial ecosystems as conservation targets.