Bacillus velezensis is not a later heterotypic synonym of Bacillus amyloliquefaciens; Bacillus methylotrophicus, Bacillus amyloliquefaciens subsp. plantarum and ‘Bacillus oryzicola’ are later heterotypic synonyms of Bacillus velezensis based on phylogenomics

Bacillus velezensis was previously reported to be a later heterotypic synonym of Bacillus amyloliquefaciens , based primarily on DNA-DNA relatedness values. We have sequenced a draft genome of B. velezensis NRRL B-41580 T . Comparative genomics and DNA-DNA relatedness calculations show that it is not a synonym of B. amyloliquefaciens. It was instead synonymous with Bacillus methylotrophicus. ' Bacillus oryzicola ' is a recently described species that was isolated as an endophyte of rice ( Oryza sativa ). The strain was demonstrated to have plant-pathogen antagonist activity in greenhouse assays, and the 16S rRNA gene was reported to have 99.7 % sequence similarity with Bacillus siamensis and B. methylotrophicus , which are both known for their plant pathogen antagonism. To better understand the phylogenetics of these closely related strains, we sequenced the genome of ' B . oryzicola ' KACC 18228. Comparative genomic analysis showed only minor differences between this strain and the genomes of B. velezensis NRRL B-41580 T , B. methylotrophicus KACC 13015 T and Bacillus amyloliquefaciens subsp. plantarum FZB42 T . The pairwise in silico DNA-DNA hybridization values calculated in comparisons between the strains were all greater than 84 %, which is well above the standard species threshold of 70 %. The results of morphological, physiological, chemotaxonomic and phylogenetic analyses indicate that the strains share phenotype and genotype coherence. Therefore, we propose tha B. methylotrophicus KACC 13015 T , B. amyloliquefaciens subsp. plantarum FZB42 T , and ' B. oryzicola' KACC 18228 should be reclassified as later heterotypic synonyms of B. velezensis NRRL B-41580 T , since the valid publication date of B. velezensis precedes the other three strains.