Phylogenetic and Functional Substrate Specificity for Endolithic Microbial Communities from the Atacama Desert

Under extreme water deficit, large thermal fluctuation, and high solar radiation fluxes, endolithic (inhabiting rock) microbial ecosystems are considered environmental refuges for life in cold and hot deserts around the world. Metagenomics analysis of two rock substrates, calcite (calcium carbonate) and ignimbrite (volcanic rock), revealed that the communities were dominated by Cyanobacteria, Actinobacteria, and Chloroflexi, but that the relative distribution of these phyla was significantly different between the two substrates.