Isolation of Lactobacillus strains with probiotic potential from camels milk

The study aimed to isolate and evaluate the probiotic potential of Lactobacillus species from fresh and fermented camel’s milk samples. Isolates were identified morphologically and biochemically. Biochemical features investigated included temperatures, pH and NaCl concentrations effects on growth, survival in simulated gastrointestinal tract conditions, bacteriocin like activity and antibiotic resistance of the tested strains. Thirty four (34) isolates coded M1 to M 34 belonging to different Lactobacillus species (41% Lactobacillus paracasei ssp. paracasei, 23% Lactobacills plantarum, 18% Lactobacillus rhamnosus, 12% Lactobacillus fermentum, 6% Lactobacillus brevis) were subjected to the above criteria. All isolates grew well at 37°C and pH 3.9 and 9.6, while they varied in growth at 10 and 45°C. However, all failed to grow after 3 h exposure to gastric juice at pH 2.0 but growth variations were obsereved after 3 h exposure at pH 3.0 followed by 4 h exposure to simulated intestinal juice of pH 8.0. Lactobacillus fermentum isolates M 1, M 2, M 4 recorded best survival rates. NaCl was tolerated by all isolates whereas elevated concentrations affected growth differently to the point of inhibition at 10%. Bacteriocin like activity was highest by Lactobacillus paracasei ssp. paracasei M 27 against MRSA and lowest by Lactobacillus fermentum M 1 against Bacillus cereus and Salmonella typhimurium. Testing for antibiotic susceptibility showed 6 out of 14 strains to be resistant to all antibiotics under study. However, Lactobacillus paracasei ssp. paracasei M 15 was sensitive to all except tetracycline. Other isolates varied, being susceptible to between 1 and 4 antibiotics. These results show the in vitro probiotic potential of Lactobacillus isolates from camel milk and further in vivo investigations are needed. Key words: Camel milk, probiotics, Lactobacillus, functional characteristics.