Probiotic Potential of Bacterial Isolates From “Amabere Amaruranu”, a Kenyan Traditional Cultured Milk

A study was conducted to isolate and identify bacteria from “amabere amaruranu” cultured-milk from Kenya and to evaluate the isolates’ potential to be used as probiotics. Isolates were identified using PCR sequence analysis of the 16S rRNA gene and the API® 50 identification system. Identified isolates included: Acetobacter tropicalis, Bacillus pumilus, Bacillus safensis, Lactobacillus paracasei, Lactobacillus rhamnosus, Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus sciuri. Their potential as probiotics was evaluated using their ability to survive in acid-then-bile conditions, antibacterial activity (against Escherichia coli, Klebsialla pneumonia, Enterococcus faecalis, Pseudomonas aeruginosa and Enterobacter cloacae), mucin degradation activity, and sensitivity to antibiotics (ampicillin, bacitracin, chloramphenicol, erythromycin, kanamycin, penicillin, streptomycin and tetracycline). Lactobacillus isolates were tolerant to acid-then-bile conditions, non-mucinolytic and inhibited growth of indicator strains but only L. rhamnosus was sensitive to all test antibiotics. Bacillus isolates were tolerant to acid-then-bile conditions, non-mucinolytic, lacked antibacterial activity and only B. safensis was sensitive to all test antibiotics. Acetobacter tropicalis isolates were non-mucinolytic but were intolerant to acid-then-bile conditions. In conclusion, both Lactobacillus rhamnosus and Bacillus safensis isolates that showed tolerance to digestive tract conditions, were sensitive to antibiotics and were non-mucinolytic would be recommended for further consideration as candidate probiotics