Microbial resources and interactions across three-dimensional space for a freshwater ecosystem

Freshwater ecosystems are important natural resources but face serious threats. Nevertheless, they host diverse microorganisms crucial for biosynthetic potential and global biochemical cycles. To fully understand the enrichment and interaction of species and functional resources in freshwater ecosystems, it is essential to profile the microbial resources in the whole three-dimensional space. We profiled 131 metagenomic samples to construct the Honghu Microbial Catalog, comprising 2617 metagenome-assembled genomes, 1718 candidate species, over 60 million non-redundant gene clusters, and 7396 biosynthetic gene clusters. We emphasized surface water may be the primary source of microbial species and ARGs for Honghu Lake. We also found the impact of surface water on groundwater had an "influence sphere". Furthermore, we have identified groundwater as a potential refuge for microbial resources, enriched with CPR bacteria and ARGs. These findings are crucial for the understanding, management, and protection of freshwater ecosystems.