16S-23S rRNA internal transcribed spacers as molecular markers for the species of the 16s rRNA group I of the genes Bacillus

The internal transcribed spacers between the 16S and the 23S ribosomal RNA genes were used to discriminate species of the 16S rRNA group I of the genus Bacillus by PCR. The spacer-PCR fingerprints clearly discriminated the different species, except those closely related like the members of the `B. cereus group' (B. cereus, B. thuringiensis and B. mycoides) and the species of the `B. subtilis group' (B. amyloliquefaciens and B. licheniformis). Examining in more detail the shortest internal transcribed spacers, B. subtilis group species were distinguished by single-strand conformation polymorphism analysis, whereas B. mycoides was differentiated from B. cereus/B. thuringiensis by restriction analysis.