COMPARATIVE SEQUENCE ANALYSES OF THE GENES-CODING FOR 16S RIBOSOMAL-RNA OF LACTOBACILLUS CASEI-RELATED TAXA

The primary structures of the 16S rRNA genes of the type strains of La ctobacillus casei and related taxa were determined by PCR DNA-sequenci ng methods. The sequences of Lactobacillus casei, Lactobacillus zeae, Lactobacillus paracasei, and Lactobacillus rhamnosus were different. T he K-nuc values ranged from 0.0040 to 0.0126. On the basis of the K-nu c values and the levels of DNA-DNA relatedness among the strains of th ese species, the L. casei-related taxa should be classified in the fol lowing three species: L. zeae, which includes the type strains of L. z eae and L. casei; a species that includes the strains of L. paracasei and L. casei ATCC 334; and L. rhamnosus.