Genomic evidence that Shouchella miscanthi (Shin et al. 2020) Joshi et al. 2022 is a later heterotypic synonym of Shouchella hunanensis (Patel and Gupta 2020) Joshi et al. 2022.

Abstract

Shouchella hunanensis DSM 23008T and Shouchella miscanthi AK13T were originally described from forest soil and the rhizosphere of Miscanthus sacchariflorus, respectively. The two strains share closely similar phenotypic properties, and their 16S rRNA gene sequences show 99.5% similarity. Phylogenetic analysis of all 16S rRNA gene copies revealed copy-dependent placements, whereas the phylogenomic analysis placed the two type strains and three additional genomes in a strongly supported, short-branched cluster. Eight 16S rRNA gene copies were identified in each genome, with detectable intragenomic heterogeneity, particularly in AK13ᵀ. Pairwise average nt identity among the two type-strain genomes and three additional publicly available genomes ranged from 99.0% to 99.3%, clearly above the accepted species boundary. The digital DNA-DNA hybridization value between strains S. hunanensis DSM 23008T and S. miscanthi AK13T was 92.5%. On the basis of the combined phylogenetic, genomic and phenotypic evidence, S. miscanthi (Shin et al. 2020) Joshi et al. 2022 is proposed as a later heterotypic synonym of S. hunanensis (Patel and Gupta 2020) Joshi et al. 2022.