Evaluation of Probiotic Properties of Anti-Microbial Exopolysaccharide Producing Lacticaseibacillus sp. AS۲۰(۱)

Background and Aim : Lactic acid bacteria are the most common microorganisms applied as probiotics. Probiotic microorganisms should possess properties to confer their beneficial effects. Acid resistance, attachment to epithelial cells, and prevention of pathogen colonization on the intestinal surface are some of these properties. Also, they should have no hemolysis and transmissible antibiotic resistance to be recognized as safe.Methods : Lacticaseibacillus sp. AS۲۰(۱) was isolated from a screening study as an anti-microbial EPS-producing isolate. In the current study, we aimed to evaluate its probiotic properties. For this purpose, its resistance to acidic pH (۲ and ۳), cell surface hydrophobicity, autoaggregation, and coaggregation abilities with Listeria monocytogenes, Yersinia eterocolitica, Bacillus cereus, and Salmonella enterica subsp. enterica were evaluated. Finally, the safety of this strain was assessed via studying its hemolysis activity and antibiotic susceptibility. Results : Lacticaseibacillus sp. AS۲۰(۱) showed excellent survival at pH ۲.۰ and ۳.۰. It showed more than ۷۱% survival rate after incubation at pH ۲.۰ and ۳.۰ for ۲ h. It showed a hydrophobicity value of ۴۷.۵%. and indicated ۶۵.۶%, ۷۱.۲% and ۹۲.۶% autoaggregation after ۲, ۳, and ۲۴ h incubation, respectively. Also, it exhibited more than ۳۵% and ۴۵% coaggregation ability after ۳ and ۲۴ hr incubation with all tested bacterial pathogens, respectively. It was susceptible to all tested antibiotics (diameter of growth inhibition zones> ۲۱ mm). Lacticaseibacillus sp. AS۲۰(۱) whit no hemolytic activity can be generally accepted as safe.Conclusion : Lacticaseibacillus sp. AS۲۰(۱) can be considered a promising probiotic strain with potential application in food industries.

Keywords:

Lacticaseibacillus sp. AS۲۰(۱) , Probiotic properties , Lactic acid bacteria