Microbial Hotspots in Lithic Microhabitats Inferred from DNA Fractionation and Metagenomics in the Atacama Desert

The existence of microbial activity hotspots in temperate regions Earth is driven by soil heterogeneities, especially the temporal and spatial availability nutrients. Here we investigate whether also exist lithic microhabitats one most arid world, Atacama Desert Chile. While previous studies evaluated total DNA fraction to elucidate communities, here for first time use a separation approach on microhabitats, together with metagenomics other analysis methods (i.e., ATP, PLFA, metabolite analysis) specifically gain insights living potentially active community. Our results show that hypolith colonized rocks are desert environment. In contrast, our data do not support such conclusion gypsum crust salt rock environments, because only limited could be observed. community dominated phototrophs, mostly Cyanobacteria Chloroflexi, at both study sites. crusts methylotrophs heterotrophic (halite nodules) phototrophic halotolerant endoliths, Archaea. major environmental constraints organic-poor hyperarid water UV irradiation, allowing phototrophs extremophiles play key role ecology.