Genome-based reclassification of Micromonospora veneta Kaewkla et al. 2022 as a later heterotypic synonym of Micromonospora coerulea Jensen 1932 (Approved Lists 1980)

In this study, we aimed to clarify the taxonomic positions of Micromonospora veneta DSM 109713^T and Micromonospora coerulea JCM 3175^T using whole-genome phylogenetic analysis, pangenomic analysis and chemotaxonomic characteristics. The 16S rRNA gene sequences of M. veneta DSM 109713^T and M. coerulea JCM 3175^T were highly similar (99.2%), and in the phylogenetic trees constructed using whole genome sequences and 16S rRNA gene sequences, M. veneta DSM 109713^T and M. coerulea JCM 3175^T clustered together and formed a clade. The values of average amino acid (AAI), average nucleotide identity (ANI), and digital DNA-DNA hybridization (DDH) between M. veneta DSM 109713^T and M. coerulea JCM 3175^T were below 97.57%, 98.29%, 85.0%, respectively, all of thresholds are greater than the threshold used for species delimitation (AAI: 95.5%, ANI: 95–96%, and DDH:70%). Most phenotypic and chemotaxonomic features between the two species were similar, with only a few differences. Based on the combined evidence from genomic and phenotypic comparison, we propose Micromonospora veneta as a later heterotypic synonym of Micromonospora coerulea.