Endolithic communities in gypcrete from the Atacama Desert

Endolithic microhabitats have been described as the last refuge for life in arid and hyper-arid deserts where life has to deal with harsh environmental conditions. In this work, three different endolithic microhabitats are described, each one with a particular origin and architecture, found within a lithic substrate known as gypcrete. Gypcrete, an evaporitic rock mainly composed of gypsum and collected in the Cordon de Lila area of the desert, was found to harbor cryptoendolithic (pore spaces in the rock), chasmoendolithic (cracks and fissures) and hypoendolithic (microcave-like pores in rock-bottom layer) microhabitats. A combination of microscopy investigations strategies and high-throughput sequencing approaches were used to characterize the endolithic communities at the microscale in different microhabitats within the same piece of lithic substrate.