Metagenome from a deep subsurface, shale-hosted aquifer of the Volcanic Eifel

High CO2 subsurface environments harbor a great diversity of archaea and bacteria, yet the microbial metabolism in these environments and its dependence on the geochemistry remains little understood. Here, we propose to analyze the metabolic potential of organisms in subsurface fluids from a high-CO2 geyser located in central Europe (Andernach Geyser) and perform a comparative analysis with a recently investigated high-CO2 geyser in USA (Crystal Geyser; work performed under a Deep Life subaward, G-2016-20166041). The two geysers are similar in their geochemical composition, yet initial microscopy analyses provide evidence that the Andernach Geyser is heavily dominated by prokaryotes of large cell sizes. While this geyser taps into a single shale-hosted aquifer of the european Volcanic Eifel, Crystal Geyser is fed by at least three different aquifers, whose individual microbiome compositions have already been resolved. Metagenomics of three samples from sequential eruptions of the Andernach Geyser will be used to reconstruct genomes of individual species. The relative abundance of metabolic pathways in these subsurface fluids will be linked to the geochemistry and compared to existing results of ca. 1200 genomes from Crystal Geyser using univariate and multivariate statistics. The anticipated results will not only provide insight into the genetic diversity of cold, high-CO2 geysers but also enable us to determine the influence of geochemical factors on metabolic pathway preferences including carbon fixation in the deep terrestrial subsurface. Project PIs, Alexander Probst and Till Bornemann.