An ANI gap within bacterial species that advances the definitions of intra-species units

ABSTRACT Large-scale surveys of prokaryotic communities (metagenomes), as well as isolate genomes, have revealed that their diversity is predominantly organized in sequence-discrete units that may be equated to species. Specifically, genomes of the same species commonly show genome-aggregate average nucleotide identity (ANI) >95% among themselves and ANI <90% to members of other species, while genomes showing ANI 90%–95% are comparatively rare. However, it remains unclear if such “discontinuities” or gaps in ANI values can be observed within species and thus used to advance and standardize intra-species units. By analyzing 18,123 complete isolate genomes from 330 bacterial species with at least 10 genome…

• NS
  National Science Foundation

  Awards: 1759831, 2129823
• MD
  Ministerio de Ciencia, Innovación y Universidades
• M
  Max-Planck-Gesellschaft
• UI
  Universität Innsbruck
• ER
  European Regional Development Fund