分别利用荧光定量PCR及平板菌落计数法计数农家干酪中双歧杆菌的菌体数,通过对结果的比较分析,建立一种适用于快速、敏感、特异的检测干酪中双歧杆菌活菌数的方法。利用传统工艺制备双歧杆菌农家干酪,在其贮存期间分别采用荧光定量PCR及平板菌落计数法计数干酪中双歧杆菌的数量。其中,在利用荧光定量PCR法检测时,对影响PCR定量准确的因素进行系统研究,包括设计双歧杆菌引物,并对引物特异性进行评价、考察,从干酪基质中提取DNA的数量和质量,建立标准曲线。引物特异性验证结果表明,引物专一性强。采用试剂盒法从干酪样品中提取DNA的纯度较好,OD_(260)/OD_(280)均在1.75~1.82之间。除贮存第1天外,荧光定量PCR法计数结果比平板计数法高0.39%~2.25%,未见显著差异。荧光定量PCR具有灵敏、特异、简便和快速的特点,可用于干酪中双歧杆菌的定量检测。 The numbers of bifidobacteria in farm cottage cheese were counted by fluorescence quantitative PCR and plate colony counting respectively. By comparative analysis of the results, a method was established to detect the viable count of bifidobacteria in cheese quickly, sensitively and specifically method. The Bifidobacterium farm cheese was prepared by the traditional process, and the quantity of bifidobacteria in the cheese was counted by fluorescence quantitative PCR and plate colony counting during storage. Among them, the use of fluorescence quantitative PCR assay, the factors that affect the quantitative PCR to conduct a systematic study, including the design of Bifidobacterium primers, and primer-specific evaluation, inspection, extracted from the cheese matrix DNA quality and quantity, Establish a standard curve. Primer specificity verification results show that the primer specificity. The purity of the DNA extracted from the cheese samples by the kit method was better, with OD 260 / OD 280 of 1.75-1.82. In addition to the first day of storage, the results of fluorescence quantitative PCR method was 0.39% ~ 2.25% higher than the plate counting method, no significant difference. Fluorescent quantitative PCR has the characteristics of sensitivity, specificity, simplicity and rapidness, and can be used for the quantitative detection of bifidobacteria in cheese.