Assessing the Acid and Bile Tolerance of Probiotic Cheese Fermentation Strains by the Method of Biological Engineering Technology

Bifidobacterium longum QYW-LB01 and Bifidobacterium animalis subsp. Lactis QYW-BB06 were regarded as the research subject to evaluate effects of pH (1.5, 2.5, 3.5, 4.5) and bile salt (1, 2, 3, 4 g/L) on their viability. Additionally, their growth curves were also investigated. Results demonstrated that Bifidobacterium had strong tolerance to simulate gastric juice and bile salts, and B. Animalis subsp. Lactis QYW-BB06 displayed better acid tolerance as compared to B. Longum QYW-LB01. The growth curves of two Bifid bacteria suggested that the viability of B. Longum QYW-LB01 was better than B. Animalis subsp. Lactis QYW-BB06 in improved MRS broth. The result may contribute to the development of probiotics cheese with sufficient numbers of Bifid bacteria.