Genome-based reclassification of Kineococcus aureolus Xu et al. 2017 as a later heterotypic synonym of Kineococcus terrestris Xu et al. 2017.

We aimed to elucidate the relationship between Kineococcus terrestris and Kineococcus aureolus through whole-genome-based analysis. The genome-derived 16S rRNA gene sequences of K. terrestris KCTC 39738^T and K. aureolus KCTC 39739^T shared a 100% similarity. Phylogenetic trees based on 16S rRNA gene and whole-genome sequences revealed that K. terrestris KCTC 39738^T and K. aureolus KCTC 39739^T formed a robust clade, indicating a close relationship between them. Genomic comparison showed that the two strains shared 99.1% average nucleotide identity, 92.0% digital DNA-DNA hybridization and 98.9% average amino acid identity values, all of which exceeded the recommended threshold values for species classification. Most phenotypic characteristics between the two species were almost identical. Based on the above evidence, we propose the reclassification of Kineococcus aureolus Xu et al. 2017 as a later heterotypic synonym of Kineococcus terrestris Xu et al. 2017. Since these two species were proposed in the same article, the principle of priority does not apply. Our proposal is supported by the fact that the nomenclatural authorities first described Kineococcus terrestris.