Rapid species identification within two groups of closely related lactobacilli using PCR primers that target the 16S/23S rRNA spacer region

A rapid and reliable PCR-based method for distinguishing closely related species within two groups of lactobacilli is described. Primers complementary to species-specific sequences in the 16S/23S rDNA spacer regions were designed after sequencing and sequence comparison of the spacer regions of 32 strains. The strains belong to two groups of closely related Lactobacillus species; one composed of Lactobacillus curvatus, Lactobacillus graminis and Lactobacillus sake, the other of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum. PCR assays with the designed primers and subsequent agarose gel analysis of the amplified fragments allowed the same species identification as the DNA/DNA hybridization procedure.