Isolation, functional activity, and safety of probiotics from Ethiopian traditional cereal-based fermented beverage, "Borde"

Yeast and lactic acid bacteria (LAB) were isolated from Ethiopian traditional fermented beverage, borde and evaluated for their potential probiotic properties, bile salt hydrolase (BSH) activity, cholesterol-lowering ability and antioxidant activity. Eleven LAB and thirteen yeast strains were selected based on their BSH activity and subjected for further examination. The results showed that LAB strains WS07, AM15, and AM20 exhibited a strong potential to lower cholesterol (85-90%), while yeast strains WS15, AA19, AM18, and AM23 showed the highest cholesterol removal (82-89%). All strains demonstrated strong antioxidant activity and survived simulated gastrointestinal tract (GIT) conditions. Four LAB and six yeast isolates were selected as the most promising probiotics based on their ability to resist simulated GIT environments. Safety evaluation revealed that none of the strains exhibited undesirable hemolytic activity or mucin hydrolysis. LAB strains were not resistant to most tested antibiotics except for vancomycin, gentamycin, and streptomycin, whereas yeast isolates were resistant to all antibiotics. The LAB strains WS07, AA13 and AM20, were identified as Pediococcus acidilactici, while, yeast isolates WS15 and AM18 were identified as Saccharomyces cerevisiae, and AA19 as Pichia cecembensis. Pediococcus acidilactici WS07 and Saccharomyces cerevisiae AM18 were identified as potential probiotic strains for cholesterol reduction.