Isolation and identification of potentially probiotic Lactobacillus strains from kefir

Recent research has shown the microbiota resident in the human gut to play a crucial role in health, and this has in turn sparked interest in developing so-called probiotic foods. Lactobacilli, the predominant microflora in kefir, are one of the probiotic microbial genera that have received the most attention to date. Kefir samples were analysed at different times during storage in order to collect potentially probiotic lactobacillus strains. REP-PCR analysis identified 5 Lactobacillus species, Lb. kefiri, Lb. plantarum, Lb. paraplantarum, Lb. gasseri, and Lb. fermentum. Three Lb. gasseri strains with different genetic profiles and two Lb. plantarum strains with different genetic profiles were isolated. These two potentially probiotic species were found to be present over the entire storage period considered. However, consumption of kefir after 2 days of storage is recommended because of the high percentage of Lb. gasseri strains present and the better sensory quality of the product on that date.