Functional stratification and enzymatic arrangement in microbial communities across a hypersaline depth gradient

作者：C. Hoepfner, Daniel Guzmán, Boris Vidal‐Veuthey, V. Foronda, Antonia Beggs, Juan Pablo Cárdenas, Virginia A. Vargas, Fernando D. Alfaro · 发表于：Frontiers in Microbiology · 年份：2025 · DOI：10.3389/fmicb.2025.1624058 · 被引用次数：5 · 研究领域：Microbial Community Ecology and Physiology、Polar Research and Ecology、Genomics and Phylogenetic Studies

Extreme environments comprise a significant portion of Earth's terrestrial surface, posing challenges, such as extreme temperatures, pressure, pH extremes, oxygen and nutrient scarcity, and high salinity. Hypersaline ecosystems, such as those in the Andean Cold Deserts, exemplify extreme environments where microbial life has evolved specialized survival mechanisms. The Central Andean Mountains host extensive salt flats exposed to extreme temperature fluctuations, intense ultraviolet radiation, and high soil salinity. While most studies focus on surface layers, the impact of soil depth on functional diversity remains poorly understood. This study utilized shotgun metagenomics and functional annotation to explore enzymatic diversity across a 8-meter depth gradient in the Uyuni Salt Flat aiming to understand microbial adaptations to depth and abiotic stress. Our findings revealed a complex, stratified microbial ecosystem. Surface layers showed high abundance of amylases, enzymes that degrade accessible carbohydrates, likely derived from photosynthetic communities or surface-imported organic matter. These patterns suggest a dominance of strategies for rapid carbon decomposition. Intermediate depths exhibited elevated lipase and peroxidase activity, reflecting the presence of complex lipids and oxidative stress management, essential for survival in oxygen-limited, high-salinity zones. Lipase support lipid utilization as a carbon source, while peroxidase activity points to redox ad...