Genome-Resolved Metagenomics Reveals Thermophilic Microbial Diversity and Putative Hydrolase-Encoding Genes in the El...

Geothermal ecosystems constitute important reservoirs of thermophilic microorganisms and their associated metabolic functions; however, the genome-resolved diversity and enzymatic potential of high-altitude geothermal systems remain poorly characterized. Here, we applied shotgun metagenomics and genome-resolved approaches to investigate thermophilic microbial communities inhabiting geothermal sediments from the El Tatio geothermal field, a polyextreme hydrothermal system located at ~4300 m above sea level in the Andean Altiplano of northern Chile. Genome reconstruction yielded 657 metagenome-assembled genomes (MAGs), including 190 near-complete and 273 high-quality genomes, providing a comprehensive genome-resolved view of microbial diversity in this environment. Taxonomic analyses revealed diverse archaeal and bacterial communities dominated by members of Thermoproteota, Methanobacteriota, Deinococcota, and Actinomycetota. Functional screening identified 612 high-confidence putative hydrolase-encoding genes distributed across multiple thermophilic lineages, including genes associated with esterases, lipases, proteases, and glycoside hydrolases. Notably, several candidates were recovered from archaeal MAGs affiliated with Thermoproteus, Sulfolobales, Pyrobaculum, and Acidilobaceae, expanding the genomic repertoire of putative hydrolytic functions in thermophilic archaea. Sequence-based thermostability prediction identified proteins with estimated melting temperatures exceeding 80 °C, with the highest predicted value reaching 87.6 °C. Collectively, these results expand current knowledge of microbial diversity and functional potential in high-altitude geothermal ecosystems and identify El Tatio as a rich source of putative hydrolase-encoding genes for future biochemical and biotechnological exploration.