Analysis on the count of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in yogurt by real-time fluorescent quantitative PCR.

The count of Lactobacillus delbrueckii and Streptococcus thermophilus in yogurt by real-time fluorescent quantitative PCR was detected in this study.The standard curve of Lactobacillus delbrueckii L2 from real-time PCR was Y=-2.936logX+34.72(R2=0.998),The standard curve of Streptococcus thermophilus S1 from Real-time PCR was Y=-3.039log X+35.45(R2=0.995).The viable counts of L2 and S1 from plate detection were respectively 8.82×108 mL-1,1.08×108 mL-1;The result from real-time PCR were respectively 8.78×108 mL-1,1.06×108 mL-1.The real-time fluorescent quantitative PCR was fit for the detection for lactic acid bacteria in yogurt.