Novel autochthonous lactobacilli with probiotic aptitudes as a main starter culture for probiotic fermented milk

This study focused on the selection of probiotic lactobacilli as main starter culture for production of probiotic fermented milk without application of any commercial ones. Forty-four Lactobacillus strains were examined in-vitro for potential probiotic properties and their application in functional food formulations. Susceptibility was observed in strains to 13 antibiotics, but none of the isolates were sensitive to ciprofloxacin. The tolerance of the strains Lactobacillus plantarum DP3, Lactobacillus casei DP21 and DP25, and Lactobacillus brevis DP30 and DP31 to bile salts and low pH was more than 68.0 ± 0.5 and 69.3 ± 0.3%, respectively and they adhered to Caco-2 cells with values ranged from 15.5 to 33.2%. These strains showed remarkable auto-aggregation capacity with values ranging more than 74%. They showed the highest cholesterol removal capability without any hemolytic activity. Strain DP3 showed the inhibitory activity against all tested pathogens. These five strains, especially DP3 and DP21, demonstrated remarkable probiotic properties and were suitable for application in functional food formulations. The results were promising as the use of the isolates DP3 and DP21 reduced the fermentation time to 10 h. The microbial count of the final products (CFU > 108) ensured their probiotic activity after 24 days of storage.