DIFFERENTIATION OF LACTOBACILLI OCCURRING IN FERMENTED MILK-PRODUCTS BY USING OLIGONUCLEOTIDE PROBES AND ELECTROPHORETIC PROTEIN PROFILES

Rapid identification of Lactobacillus species that are used as starter organisms for fermented milk products was achieved by applying 23S rR NA-targeted oligonucleotide probes and numerical analysis of gel elect rophoretic protein profiles. 23S rRNA genes of various lactobacilli we re partially sequenced and complementary specific oligonucleotide prob es were synthesised. Species specific probes for Lactobacillus delbrue ckii, L. helveticus, and L. paracasei and group specific probes for L. caseil/L. rhamnosus and L. casei/L. paracasei/L. rhamnosus were desig ned. Moreover, the lactobacilli strains were examined by polyacrylamid e gelelectrophoresis of sodium dodecylsulphate denatured whole-cell pr oteins. After numerical comparison of the resulting electrophoretic pr otein patterns, definite clusters could be determined, correlating wel l with the different species.