The lactic acid bacteria are used in fermentation and the bio conservation of food, because it produces organic acids and other antibacterial substances as the bacteriocin to inhibit certain pathogenic stocks. In orde...The lactic acid bacteria are used in fermentation and the bio conservation of food, because it produces organic acids and other antibacterial substances as the bacteriocin to inhibit certain pathogenic stocks. In order to demonstrate the inhibitory effect of these bacteria, we studied the antagonistic capacity of the two leavens of yoghourt （Streptococcus thermophilus and Lactobacillus bulgaricus） and Bifidobacterium bifidum with respect to Helicobacterpylori by the method of diffusion by discs. Their interactions led to the emergence of large zones of inhibition. Bifidobacterium bifidum led the greatest halo with a diameter of 0.8 cm by contribution to Lactobacillus bulgaricus （0.5 cm） and Streptococcus thermophilus （0.3 cm）. The additional tests were required to know the exact nature of the inhibitors. The results showed that the antibacterial peptides （bacteriocins） have a narrow spectrum of activity against the species pathogen compared to that caused by acidity.展开更多
文摘The lactic acid bacteria are used in fermentation and the bio conservation of food, because it produces organic acids and other antibacterial substances as the bacteriocin to inhibit certain pathogenic stocks. In order to demonstrate the inhibitory effect of these bacteria, we studied the antagonistic capacity of the two leavens of yoghourt （Streptococcus thermophilus and Lactobacillus bulgaricus） and Bifidobacterium bifidum with respect to Helicobacterpylori by the method of diffusion by discs. Their interactions led to the emergence of large zones of inhibition. Bifidobacterium bifidum led the greatest halo with a diameter of 0.8 cm by contribution to Lactobacillus bulgaricus （0.5 cm） and Streptococcus thermophilus （0.3 cm）. The additional tests were required to know the exact nature of the inhibitors. The results showed that the antibacterial peptides （bacteriocins） have a narrow spectrum of activity against the species pathogen compared to that caused by acidity.
