Bacillus velezensis is a later heterotypic synonym of Bacillus amyloliquefaciens

Abstract

Strain BCRC 14193, isolated from soil, shared more than 99 % 16S rRNA gene sequence similarity with Bacillus amyloliquefaciens BCRC 11601(T) and Bacillus velezensis BCRC 17467(T). This strain was previously identified as B. amyloliquefaciens, based on DNA-DNA hybridization, but its DNA relatedness value with B. velezensis BCRC 17467(T) 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 17467(T) 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 17467(T) and B. amyloliquefaciens BCRC 11601(T) (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.