Proposal of Biavati 1992 as a later heterotypic synonym of Watabe 1983 and subsp. subsp. nov.

In 2018, Nouioui transferred and to as subsp. and subsp. on the basis of digital DNA-DNA hybridization (dDDH) values. These two new subspecies were validated in the same year. However, we found that the genome (GenBank/ENA/DDBJ accession number JGZJ01000000) of used by Nouioui in the dDDH analysis cannot represent . So, the taxonomic relationship between , and should be re-examined. DSM 20433 had 88.7-89.0 % average nucleotide identity (ANI) values and 37.5-38.0 % dDDH values to the type strains of and , respectively, less than the threshold for species demarcation, confirming that represents a different species from and . The ANI values and dDDH values between the type strains of and were 96.7-96.9 % and 73.0-73.3 %, respectively, greater than the threshold for species demarcation, confirming that they represent the same species. Relatively low dDDH values (less than the 79-80 % threshold for subspecies demarcation) between the type strains of and indicated that can be considered as a subspecies of . On the basis of the results presented here, (i) and should not be transferred to ; (ii) we propose Biavati 1992 as a later heterotypic synonym of Watabe 1983 and as a new subspecies of , for which the name subsp. subsp. nov. is proposed.