Fig. 1

The composition of dominant microbial groups (top 30 abundant across all samples). a Microbial community shifts at order level with depth. b Microbial community shifts at genus level with depth. The analysis is based on the metagenomic data annotation against the NCBI-nr database. Sample names are defined by size fraction and sampling depth, e.g., FL10500 is the free-living fraction at 10,500 m. Dot size in the panel a is proportional to the relative abundance of microbial groups. The relative abundance at the genus level was rank transformed. The genera shadowed in blue indicate significant enrichment in the four NBW samples. The bar plot at the right side shows the average proportion (across the four NBW samples) of each genus in the total microbial population