Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40793-021-00395-w/MediaObjects/40793_2021_395_Fig1_HTML.png)
Community composition of the groundwater samples based on metagenomic reads mapped against the SILVA (SSU rRNA Ref NR99) database. Each column represents a metagenomic sample replicate for specified filter fractions from respective wells of the limestone-mudstone strata that host the multi-story upper aquifer assemblage (HTU; wells H14, H32, H43, H52) and the karstified main aquifer (HTL; wells H41, H51)