Screening of Lactobacillus spp. from raw goat milk showing probiotic activities against pathogenic bacteria

This research work was executed to isolate potential Lactobacillus spp. from local raw goat milk samples for their antimicrobial activities against different human intestinal pathogens. Isolation of such bacteria was carried out by Man Rogosa Sharpe (MRS) agar media. Identification of the isolated strain was conducted according to the morphological and biochemical tests. Furthermore, growth optimization and their antimicrobial activity also studied against the pathogenic bacteria (Escherichia coli ATCC 25921, Pseudomonas aeruginosa ATCC 9027, Vibrio cholera ATCC 14035 and Salmonella enteric ATCC 14028). A total of 23 isolates were obtained from the raw goat milk samples, among them four isolates were selected on the basis of their antimicrobial activities against pathogenic bacteria. The Lactobacillus spp. showed better growth in 6.5 to 7.5 pH range and temperature range was 35 to 40°C. Thus it can be said that the goat milk provides a natural dwelling place for Lactobacillus spp., which are beneficial to human health. Key words: Antimicrobial activity, growth optimization, intestinal pathogens, Lactobacillus spp., Man Rogosa Sharpe (MRS) agar media, pH, raw goat milk.