Rapid PCR-based procedure to identify lactic acid bacteria: application tosix common Lactobacillus species

The goal of this study was to develop a method allowing rapid identificatio n of the lactic acid bacteria strains in use in the laboratory (Lactobacill us plantarum NCIMB8826; L. fermentum KLD; L, reuteri 100-23; L. salivarius UCC43321; L, paracasei LbTGS1.4: L, casei ATCC393), based on PCR amplificat ion of 16S RNA coding sequences. First, specific Forward oligonucleotides w ere designed in the variable regions of 16S RNA coding sequences of six Lac tobacillus strains. The reverse oligonucleotide was designed in the region where the sequences were homologous for the six strains. The expected size of the amplification product was +/- 1000 bp. The specificity of the method was tested on total chromosomal DNA. For five our of the six strains, the amplification of the fragment was strain-specific and the method was direct ly applicable to colonies. For the strain L. casei ATCC393, an additional a rgument to the classification of this bacteria in the paracasei group could be proposed. Validation of the developed method was performed by applying it to six Lactobacillus reference strains and to various species of bacteri a. (C) 2001 Elsevier Science B.V. All rights reserved.