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.

Abstract

The genus Actinomadura comprises Gram-positive bacteria found in diverse natural environments and is classified in the family Thermomonosporaceae within the order Streptosporangiales. 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 Actinomadura species. Actinomadura livida JCM 3387ᵀ and Actinomadura catellatispora 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 Actinomadura catellatispora Lu et al. 2003 be a later heterotypic synonym of Actinomadura livida Lavrova and Preobrazhenskaya 1975 (Approved Lists 1980).