A comprehensive catalog encompassing 1376 species-level genomes reveals the core community and functional diversity of anammox microbiota

Background The anammox process plays a key role in nitrogen removal in environmentally friendly wastewater treatment plants. However, our comprehensive understanding of the anammox process is constrained by the limited taxonomic assignment and functional characterization of anammox microbiota, primarily due to the scarcity of high-quality genomes for most microorganisms. Results Here, we report the first global genome catalog of anammox microbiotas and their enormous diversity based on 236 metagenomes. We recovered 7206 metagenome-assembled genomes (MAGs) representing 1376 candidate species, providing extensive microbial coverage (averaged of 92.40%) of anammox microbiota. Analysis of the integrated catalog demonstrated significant associations between anammox microbiota and system type, e.g., coupled systems displayed high microbial diversity and intricate interspecies interactions. We also identified 64 core genera and 44 core species, accounting for approximately 64.25% and 43.97%, respectively, of anammox microbiota. In particular, the core genera with high species diversity exhibited diverse metabolic profiles, and included functional genes for nitrogen, carbohydrate, amino acid, and vitamin metabolism. Finally, we underscored the functional diversity of the denitrifying bacteria Desulfobacillus and Zeimonas , with multiple abundant species in each genus. Conclusion The integrated catalog substantially expands our current understanding of the core community and the functional potential of anammox microbiota, providing a valuable resource for future studies on anammox systems.