以蜡样芽孢杆菌gyrB基因作为目标基因并设计特异性引物,用95 ℃预变性5 min、95 ℃变性15 s、50 ℃复性30 s、72 ℃延伸30 s,反应45个循环为反应程序,以蜡样芽孢杆菌DNA为模板进行荧光定量聚合酶链式反应(PCR),提出了食品中蜡样芽孢杆菌快速检测的方法,并对该方法特异性、蜡样芽孢杆菌DNA灵敏度以及活菌检出限进行验证。结果表明,该引物在分段扩增中可以实现对蜡样芽孢杆菌的快速检测,而且重复性好;以3种非蜡样芽孢杆菌和蜡样芽孢杆菌进行特异性试验,非蜡样芽孢杆菌均没有扩增出曲线,仅蜡样芽孢杆菌扩增出特异性曲线;蜡样芽孢杆菌DNA按10倍稀释法进行灵敏度检测,可达0.01 mg·L^-1,活菌检出限为8.9×10²CFU·mL^-1。

Bacillus cereus gyrB gene was used as the target gene, and the specific primers were designed. The reaction procedure was as follows: predenaturation at 95℃ for 5 min, denaturation at 95 ℃ for 15 s, refolding at 50 ℃ for 30 s, extension at 72 ℃ for 30 s, 45 cycles of reaction. Bacillus cereus DNA was used as the template, and a rapid method for detection of Bacillus cereus in food was proposed by fluorescence quantitative polymerase chain reaction (PCR). Tests for specificity of the method, sensitivity of Bacillus cereus DNA and detection limit of live bacteria were carried out. As shown by the results, the primer could achieve rapid detection of Bacillus cereus in segmented amplification, and had good repeatability. 3 non-Bacillus cereus and Bacillus cereus were used for specificity test, and no amplification curve was found for non-Bacillus cereus, but the specific curve was found for Bacillus cereus. Sensitivity detection was performed for Bacillus cereus DNA in 10-fold serial dilutions, giving the result of 0.01 mg·L^-1, and detection limit of live bacteria was 8.9×10²CFU·mL^-1.