Characterizing the planktonic and sedimentary communities of bacteria, archaea and eukaryotes in an urban glaciotectonic cave

The terrestrial subsurface harbors unique microbial communities that play important biogeochemical roles and allow to study a yet unknown fraction of the Earth's biodiversity. The Saint-Leonard cave in Montreal city (Quebec, Canada) is of glaciotectonic origin. Its speleogenesis traces back to the withdrawal of the Laurentide Ice Sheet, 13 000 years ago, during which the moving glacier dislocated the sedimentary rock layers. Our study is the first to investigate the microbial communities of the Saint-Leonard cave. By using amplicon sequencing, we analyzed the taxonomic diversity and composition of bacterial, archaeal and eukaryotes communities living in the groundwater (0.1um- and 0.2 um-filtered water), in the sediments and in the surface soils.