Molecular discrimination of lactobacilli used as starter and probiotic cultures by amplified ribosomal DNA restriction analysis

Lactic acid bacteria such as Lactobacillus helveticus, L. delbrueckii subsp . delbrueckii, L. delbrueckii subsp. lactis, L. delbrueckii subsp. bulgaric us, L. acidophilus, and L. casei related taxa which are widely used as star ter or probiotic cultures can be identified by amplified ribosomal DNA rest riction analysis (ARDRA). The genetic discrimination of the related species belonging to these groups was first obtained by PCR amplifications by usin g group-specific or species-specific 16S rDNA primers. The numerical analys is of the ARDRA patterns obtained by using CfoI, HinfI, Tru9I, and ScrFI wa s an efficient typing tool for identification of species of the L. acidophi lus and L. casei complex. ARDRA by using CfoI was a reliable method for dif ferentiation oft. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. l actis. Finally, strains ATCC 393 and ATCC 15820 exhibited unique ARDRA patt erns with CfoI and Tru9I restriction enzymes as compared with the other str ains of L. casei, L. paracasei, and L. rhamnosus.