hordniae containing a sequence in the Vl region that differs in only one nucleotide from that of L. lactis subsp. lactis and its variant diacetylactis (data not shown). Exactly the same substitution is found in the Vl region of some L. lactis subsp. lactis strains (14). By using the PL12 probe, these variants could also be detected (Table 2). The sequences of the Vi regions of L. lactis subsp. cremoris and L. lactis subsp. lactis show too many differences to allow the design of a species-specific L. lactis probe. The identification of Leuconostoc spp. is shown in Fig. 3. The larger size of its amplified Vl region (Fig. 3A) confirms that Leuconostoc paramesenteroides is related to the genus Lactobacillus (Vi = 110 bp), as was proposed recently on the basis of 16S rRNA comparison (18). In spite of the fact that the V3 regions of Leuconostoc lactis and Leuconostoc mesenteroides contained only three nucleotide differences, a good discrimination between these species was found with the Leuconostoc probes (Fig. 3). The specificity of these probes was also confirmed (Table 3).