Abstract:

Objective: Fourteen strains of lactic acid bacteria were identified by a series of taxonomic methods based on
16S rDNA sequence. Methods: Genomic DNAs were extracted from 14 strains. PCR amplification with Lactobacillus
genus-specific primers was employed to select Lactobacillus strains. Homology analysis of 16S rDNA sequence, speciesspecific
PCR and NEBcutter analysis were combined to indentify 14 strains to species level. Results: Except 123-2 and
23-3 all strains were identified to be Lactobacillus strains by Lactobacillus genus-specific PCR amplification. Through
homology analysis of 16S rDNA sequence, strains 11-2, 13-3, 14-3, 16-4, 23-3, 24-3, 26-1, 122-1 and 123-4 were assigned
to Lactobacillus casei or Lactobacillus paracasei, 17-5, 20-2 and 28-1 to Lactobacillus plantarum, 123-2 to Leuconostoc
mesenteroides, 125-2 to Lactobacillus parabuchneri. Except for 23-3, the results from homology analysis corresponded
well with those obtained from genus-specific PCR. Stains 11-2, 13-3, 14-3, 16-4, 23-3, 24-3, 26-1, 122-1 and 123-4 were
further confirmed to be Lactobacillus paracasei by species-specific PCR. Finally, these results were verified by NEBcutter.
Conclusion: Rapid and accurate identification of natural lactic acid bacteria to species level can be obtained by the
combinatorial application of taxonomic methods presented in this study.

Key words: lactic acid bacteria (LAB), identification, genus-specific polymerase chain reaction (PCR), 16S rDNA, species-specific PCR, NEBcutter