Data base - link
||Stoddard SF, Smith BJ, Hein R, Roller BR, Schmidt TM. rrnDB: improved tools for interpreting rRNA gene abundance in bacteria and archaea and a new foundation for future development. Nucleic Acids Res. 2014 Nov 20. pii: gku1201. link Latest release: rrnDB version 4.3.3 November 06, 2014 Last accessed May 7th 2015 PubMed ID25414355
||"A searchable database documenting variation in ribosomal RNA operons (rrn) in Bacteria and Archaea. Find information such as the 16S gene copy number of an organism by looking up its name under the NCBI or RDP taxonomy or by full-text search of rrnDB's records."
||Ref abstract: "Here [researchers] present an update to the ribosomal RNA operon copy number database (rrnDB), a publicly available, curated resource for copy number information for bacteria and archaea. The redesigned rrnDB ( link ) brings a substantial increase in the number of genomes described, improved curation, mapping of genomes to both NCBI and RDP taxonomies, and refined tools for querying and analyzing these data. With these changes, the rrnDB is better positioned to remain a comprehensive resource under the torrent of microbial genome sequencing. The enhanced rrnDB will contribute to the analysis of molecular surveys and to research linking genomic characteristics to life history."