Characterisation of potential probiotic Lactobacillus strains of human origin

Molecular biological methods (genus-specific PCR, species-specific PCRs, RAPD with primer M13, and rep-PCR with primer (GTG)5) were applied for the identification and discrimination of 31 strains of the Lactobacillus genus isolated from faecal samples of 30 breastfed infants. All strains were tested for bile salts and low pH tolerance, growth in milk, production of lactic acids in milk and milk supplemented with yeast extract, and used in biochemical tests including production of beta-glucuronidase. Consequently, the presence of genes coding for decarboxylases was investigated using PCR. Finally, four strains of probiotic species were selected for use in the dairy industry and for other tests concerning their probiotic character.