An updated bacterial and archaeal reference genome collection is available! This collection of 17,163 genomes was built by selecting exactly one genome assembly for each species among the 272,000+ prokaryotic genomes in RefSeq, except for E. coli for which two assemblies were selected as reference.
A total of 497 species are included in this collection for the first time. In addition, comparing to the October 2022 set, 174 species are represented by a better assembly and 15 species were removed because of changes in NCBI Taxonomy or uncertainty in their species assignment. The criteria for selecting one assembly for a given species from all assemblies available in RefSeq for the species include assembly contiguity and completeness and quality of the RefSeq annotation. See the documentation for details.
We have updated the nucleotide BLAST RefSeq reference genomes database (fourth in the menu) as well as the database on the Microbial Nucleotide BLAST page to reflect these changes. You can also run BLAST searches against the proteins annotated on these reference genomes (RefSeq Select proteins database, second in the menu).