Rare Worlds, Rare Microbes—From Salt Flats and Tropical Glaciers to Volcanoes and Andean Deserts as Natural Laboratories for Microbial Biotechnology in Latin America

Latin America harbours an exceptional diversity of extreme and polyextreme environments resulting from the interplay of tectonics, volcanism, climatic heterogeneity, and long-term geological evolution. Hypersaline lakes and salt flats, geothermal and volcanic systems, hyperarid deserts, high-altitude ecosystems, polar and subpolar regions, and insular Caribbean extremes together form a mosaic of natural laboratories where life persists under intense and often overlapping physicochemical stressors. In this perspective-driven review, we synthesize representative examples from across the region-including continental and insular settings such as Mexico, the Andes, Patagonia, and the Dominican Republic-to illustrate how microbial life in Latin America challenges traditional, single-stressor definitions of extremophily. Instead, these ecosystems are characterized by the convergence of salinity, temperature, pH, radiation, low water activity, nutrient limitation, and high heavy metal concentrations, selecting for microbial communities with remarkable physiological plasticity and metabolic versatility. We argue that this complexity has fostered unique adaptive strategies and functional traits with broad implications for ecology, evolution, and biotechnology, including the production of extremozymes, bioactive compounds, stress-protective and catalyst pigments, and myriad other microbial resources relevant for bioremediation and sustainable agriculture. Despite their importance, many Latin American extreme environments remain underexplored and increasingly threatened by climate change, resource exploitation, and land-use transformation. We emphasize the need for coordinated regional efforts integrating omics approaches, culture-based studies, biobanking, and interdisciplinary collaboration, while recognizing the value of local knowledge and biocultural perspectives. Preserving and studying these extreme ecosystems is essential not only for understanding the limits of life but also for unlocking their potential to inform sustainable innovation in a rapidly changing world.