Genome-based reclassification of Blautia coccoides (Kaneuchi et al. 1976) Liu et al. 2008 as a later heterotypic synonym of Blautia producta (Prévot 1941) Liu et al. 2008

In the current study, we evaluated the taxonomic relationship between <i>Blautia coccoides</i> and <i>Blautia producta</i> through a comprehensive comparison of phenotypic and genomic characteristics, as well as phylogenetic analysis. The 16S rRNA gene sequences of the type strains <i>B. coccoides</i> and <i>B. producta</i> shared a sequence similarity of 99.65%, which was above the threshold value (98.65%) for bacterial species delineation. In addition, whole-genome comparisons revealed that <i>B. coccoides</i> DSM 935^T and <i>B. producta</i> DSM 2950^T shared 97.06% average nucleotide identity by blast (ANIb), 98.38% average nucleotide identity using MUMmer (ANIm), 97.77% average amino acid identity and 84.80% digital DNA-DNA hybridization (dDDH) values. These scores exceed the threshold criteria for bacterial species delineation, strongly suggesting that these species belong to the same species. Furthermore, phylogenetic and phylogenomic analyses provided additional evidence that <i>B. coccoides</i> DSM 935^T and <i>B. producta</i> DSM 2950^T are very closely related to each other. Additionally, the phenotypic features of these species further revealed that they belong to the single species. On the basis of the results presented here and the principle of priority in nomenclature, <i>B. coccoides</i> (Kaneuchi <i>et al</i>. 1976) Liu <i>et al</i>. 2008 should be considered a later heterotypic synonym of <i>B. producta</i> (Prévot 1941) Liu <i>et al</i>. 2008.