Bacillus velezensis is a later heterotypic synonym of Bacillus amyloliquefaciens

Strain BCRC 14193, isolated from soil, shared more than 99 % 16S rRNA gene sequence similarity with Bacillus amyloliquefaciens BCRC 11601T and Bacillus velezensis BCRC 17467T. This strain was previously identified as B. amyloliquefaciens, based on DNA–DNA hybridization, but its DNA relatedness value with B. velezensis BCRC 17467T was 89 %. To investigate the relatedness of strain BCRC 14193, B. amyloliquefaciens and B. velezensis, the partial sequence of the gene encoding the subunit B protein of DNA gyrase (gyrB) was determined. B. velezensis BCRC 17467T shared high gyrB gene sequence similarity with B. amyloliquefaciens BCRC 14193 (98.4 %) and all of the B. amyloliquefaciens strains available (95.5–95.6 %). DNA–DNA hybridization experiments revealed high relatedness values between B. velezensis BCRC 17467T and B. amyloliquefaciens BCRC 11601T (74 %) and the B. amyloliquefaciens reference strains (74–89 %). Based on these data and the lack of phenotypic distinctive characteristics, we propose Bacillus velezensis as a later heterotypic synonym of Bacillus amyloliquefaciens.