Probiotics are usually used in functional foods due to their nutraceutical
effects. But before using a strain to formulate functional foods, many tests
have to be done to check some probiotic properties. Lactococcus lactis sp (L.
lactis sp) strain isolated from fermented maize beverage “Sha’a” used in this
study was grown in M17 broth for 56 h to determine the growth curve.
Tolerance to the extreme gastrointestinal conditions (pH 2.0 and bile tolerance
to 3.0%) was studied after gradual adaptation of the culture. Antibiotic
resistance and antioxidant activity were evaluated. The ability to inhibit the
growth of harmful bacteria was also checked. Results showed that culture
strain could resist pH 2.0 and 3% bile for 24 hours. L. lactis sp. was able to
produce acid which decreased the pH of the medium. Higher antioxidant
activity was observed after 18 h of incubation (47.76 ± 0.00%). The strain was
susceptible of most the antibiotics tested. Cultures presented a strong
inhibition activity against the food-borne pathogens tested (Citrobacter sp.,
Shigella sp., Shigella dysenteriae, Enterococcus feacalis, and Pseudomonas sp.).
Keywords: Lactococcus lactis sp., acid and bile salt tolerances, antibiotic
resistance, antioxidant activity, antimicrobial activity.