Note: identification of Lactobacillus delbrueckii subspecies bulgaricus and subspecies lactis dairy isolates by amplified rDNA restriction analysis.

Amplification and restriction analysis of the 16S rRNA gene (PCR-ARDRA) was used to identify Lactobacillus delbrueckii dairy isolates and to assign them to its three subspecies (delbrueckii, lactis and bulgaricus). PCR-ARDRA allowed confirmation of predictions from the DNA database regarding the restriction mapping of the 16S sequence to be verified in practice. PCR-ARDRA was shown to be a reliable and rapid method for identifying Lact. delbrueckii isolates at the subspecies level and for differentiating this species from Lact. helveticus and Lact. acidophilus.