Isolation, Characterization and Liposome-Mediated Encapsulation of Potential Probiotic Lactic Acid Bacteria Isolated...

Lactic acid bacteria (LAB) are widely used in fermented foods and have been shown to support bone health, manage diabetes, and maintain microbiota balance. In this context, probiotics are key ingredients in functional food production. The aim of this study was to determine the probiotic potential of LAB strains isolated from homemade yogurt and kefir by functional characterizations and to load the most effective probiotic into liposomes to protect against gastrointestinal conditions in further functional studies. Among the Lactiplantibacillus sp. BC-10, Lactobacillus delbrueckii subsp. bulgaricus BC-16, Lacticaseibacillus sp. BC-8, L. helveticus BC-6 isolates provided within the scope of the study and whose functional properties were determined, L. delbrueckii subsp. bulgaricus BC-16 was evaluated as a safe and functionally effective probiotic with lower cytotoxic effect (only 14-21% inhibition at 50 µL/mL and 47 - 33% inhibition at 500 µL/mL), sensitivity to antibiotic species, high exopolysaccharide production (137.61 ± 25.85) and hydrophobic ability (90.97 ± 1.49) compared to other strains at high concentrations (50-500 µL/mL). L. delbrueckii subsp. bulgaricus BC-16 isolate was loaded into liposome structures and encapsulation efficiency was found to be approximately 86.8% and post-encapsulation process efficiency was 62.5%. At the end of in vitro gastrointestinal conditions, the number of free probiotic cells decreased from 8.25 log CFU/mL to 6.50 log CFU/mL, while the number of probiotic cells in the liposome decreased from 7.07 log CFU/mL to 6.90 log CFU/mL. These results indicate that liposome structures are beneficial for probiotic viability and stability.