Development of a novel PCR assay based on the gyrase B gene for species identification of Bacillus licheniformis

Bacillus licheniformis is closely related to the Bacillus subtilis group, and could not be clearly identified using phenotypic and genotypic (16S rDNA sequence analysis) techniques alone. Some strains of this species are considered to be probiotic and are widely applied in the food and feed industry. The objective of this study was to develop species-specific PCR based on the gyrB gene sequence for direct species identification of the B. licheniformis within the B. subtilis group. A pair of species-specific primer was designed and used to specifically detect B. licheniformis, but none of the other B. subtilis group strains. Our data indicate that the novel species-specific primer could be used to rapidly and accurately identify the species of B. licheniformis from B. subtilis group by a PCR based assay.