Rapid molecular identification and characteristics of <Emphasis Type="Italic">Lactobacillus</Emphasis> strains

Eleven type strains and 24 Lactobacillus isolates, preliminarily classified to the species due to phenotypic features, were investigated. Standard methods of identification with species-specific PCRs and typing with PFGE (with ApaI, NotI and SmaI restriction enzymes) allowed us to distinguish 16 unique strains belonging to 5 species (L. acidophilus, L. delbrueckii ssp. bulgaricus, L. plantarum, L. rhamnosus, L. salivarius). Alternative approach with 16S–23S rDNA ARDRA identification (with merely two restrictases, BsuRI and TaqI) and PCR-based typing (RAPD with two random- and rep-PCR with (GTG)₅ primers) showed to be more discriminative, i.e. 21 unique strains were classified in the same species as above. As a result, 7 out of 24 phenotypically species-assigned isolates were reclassified. The alternative procedure of rapid identification and typing of Lactobacillus isolates appeared to be equally effective and shortened from 1 week to 2–3 d (in comparison to the standard methods).