Hanstruepera crassostreae He et al. 2018 is a later heterotypic synonym of Pseudobizionia ponticola Park et al. 2018 and transfer of Pseudobizionia ponticola to the genus Hanstruepera as Hanstruepera ponticola comb. nov

The 16S rRNA gene sequences of Pseudobizionia ponticola MM-14T and Hanstruepera crassostreae L53T shared 100 % sequence similarity. This study aimed to clarify the taxonomic position of the two species. Whole-genome comparisons showed that P. ponticola MM-14T and H. crassostreae L53T shared average nucleotide identity of 97.52 %, digital DNA-DNA hybridization of 75.30 % and average amino acid identity of 96.98 %. These values exceeded the threshold of bacterial species delineation. Furthermore, average amino acid identities of P. ponticola MM-14T and H. crassostreae L53T in comparison with Hanstruepera neustonica CC-PY-50T were 82.04 and 82.11 %, respectively. Phylogenetic analysis based on 16S rRNA gene and 120 bacterial conserved single-copy genes also supported that P. ponticola MM-14T and H. crassostreae L53T belonged to the genus Hanstruepera. Phenotypic and chemical taxonomic properties compared between P. ponticola MM-14T and H. crassostreae L53T were nearly identical. Colonies of the two species on marine agar plates were orange-pigmented, circular and smooth. Flexirubin-type pigments were present in both H. crassostreae L53T and P. ponticola MM-14T. The major fatty acids composition of the two species consisted of iso-C15 : 1 G, iso-C15 : 0, and iso-C17 : 0 3-OH, similar to H. neustonica CC-PY-50T. Based on priority, H. crassostreae He et al. 2018 is a later heterotypic synonym of P. ponticola Park et al. 2018, and P. ponticola should be transferred to the genus Hanstruepera as Hanstruepera ponticola comb. nov.