MIrROR release 02: Expanded and refined 16S-ITS-23S rRNA operon dataset

With the rapid advancements in genome sequencing technologies, microbial genome data has exponentially increased, making it essential to continuously update dataset for accurate microbial identification and classification. We present the development of Microbial Identification using rRNA Operon Region (MIrROR) release 02, an expanded dataset based on 1,690,470 genomes (1,674,514 bacterial and 15,956 archaeal) sourced from NCBI. The final curated dataset covers 476,579 sequences, 249,907 genomes, and 29,051 species, representing increases of 387.39%, 472.49%, and 206.28% over the previous release. Key updates include the addition of archaeal genomes and taxonomy reclassification based on GTDB R220. Extensive curation was performed, including filtering operon lengths (3,500-7,000 bp), removing duplicate sequences, eliminating sequences with ambiguous nucleotides, and clustering of sequences at 99% identity to remove redundancies. The updated dataset showed improved performance in microbial mock community analyses, supporting its accuracy and reliability. These improvements make MIrROR release 02 a valuable resource for microbial profiling and various microbiological research applications.