Reclassification of Actinomadura catellatispora Lu et al. 2003 as a later synonym of Actinomadura livida Lavrova and Preobrazhenskaya 1975 (Approved List 1980) based on whole-genome analysis

The genus <i>Actinomadura</i> comprises Gram-positive bacteria found in diverse natural environments and is classified in the family <i>Thermomonosporaceae</i> within the order <i>Streptosporangiales</i>. Some species exhibit considerable phylogenetic and taxonomic overlaps, prompting a comprehensive investigation that integrates phylogenetic, phylogenomic and comparative genomic analyses to elucidate the taxonomic status of two <i>Actinomadura</i> species. <i>Actinomadura livida</i> JCM 3387ᵀ and <i>Actinomadura catellatispora</i> DSM 44772^T shared 16S rRNA gene sequence similarity of 99.9% and digital DNA-DNA hybridization values of 99.8%. Moreover, the average nucleotide identity value for the two species was 99.8%, indicating minimal genomic variation between the two strains. Also, the distribution of carbohydrate-active enzymes and biosynthetic gene clusters predicted to code for secondary metabolites between the two species were almost identical. Data of overall genomic similarity support that <i>Actinomadura catellatispora</i> Lu <i>et al.</i> 2003 be a later heterotypic synonym of <i>Actinomadura livida</i> Lavrova and Preobrazhenskaya 1975 (Approved Lists 1980).