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.

石内生微生境（Endolithic microhabitats）被认为是干旱及超干旱荒漠中生命的最后庇护所，此类环境中的生物需应对严苛的环境条件。本研究共描述了三种不同的石内生微生境，三者均发现于被称为石膏结壳（gypcrete）的岩性基质中，各自具备独特的起源与结构特征。该石膏结壳为以石膏为主要组分的蒸发岩（evaporitic rock），采集自荒漠中的利拉科尔多（Cordon de Lila）区域，其内部孕育有三类微生境：隐石生微生境（cryptoendolithic，对应岩石内部孔隙）、缝石生微生境（chasmoendolithic，对应岩石裂隙）以及底石生微生境（hypoendolithic，对应岩底层的微洞穴状孔隙）。本研究结合显微观测技术与高通量测序（high-throughput sequencing）手段，在微观尺度下对同一块岩性基质中不同微生境的石内生群落（endolithic communities）进行了表征分析。