AUTHOR=Jung Patrick , Lehnert Lukas W. , Bendix Jörg , Lentendu Guillaume , Grube Martin , Alfaro Fernando D. , Rio Camilo del , Gutiérrez Alvarado José Luis , van den Brink Liesbeth , Lakatos Michael TITLE=The grit crust: A poly-extremotolerant microbial community from the Atacama Desert as a model for astrobiology JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2022.1052278 DOI=10.3389/fspas.2022.1052278 ISSN=2296-987X ABSTRACT=

The grit crust is a recently discovered, novel type of biocrust made of prokaryotic cyanobacteria, eukaryotic green algae, fungi, lichens and other microbes that grow around and within granitoid stone pebbles of about 6 mm diameter in the Coastal Range of the Atacama Desert, Chile. The microbial community is very well adapted towards the extreme conditions of the Atacama Desert, such as the highest irradiation of the planet, strong temperature amplitudes and steep wet-dry cycles. It also has several other striking features making this biocrust unique compared to biocrusts known from other arid biomes on Earth. It has already been shown that the grit crust mediates various bio-weathering activities in its natural habitat. These activities prime soil for higher organisms in a way that can be envisioned as a proxy for general processes shaping even extra-terrestrial landscapes. This mini-review highlights the potential of the grit crust as a model for astrobiology in terms of extra-terrestrial microbial colonization and biotechnological applications that support human colonization of planets.