本文对温度（50~100 ℃）、超声（200 W，5~30 min）、nisin（100~350 IU/mL）协同磁场强度为3.0 T，脉冲数为30个的脉冲磁场杀灭枯草芽孢杆菌进行了研究。结果表明：先脉冲磁场处理后温度处理时，温度越高，杀菌效果越好，当温度为100 ℃，枯草芽孢杆菌的残留率最低为3.17%；先脉冲磁场处理再采用超声功率800 W，工作5 s间隙10 s的超声处理后，超声总时间越长杀菌效果越好，当超声时间为30 min时，枯草芽孢杆菌的残留率最低为8.18%；先脉冲磁场处理后nisin处理时，浓度越高杀菌效果越好，当nisin终浓度为350 IU/mL时，枯草芽孢杆菌的残留率最低为19.21%；先脉冲磁场处理再温度、超声、nisin处理的杀菌效果比先温度、超声、nisin处理后再脉冲磁场处理的杀菌效果要好，这与扫描电镜的观察结果相吻合。协同杀菌后，枯草芽孢杆菌的形态发生改变，细胞产生萎缩现象，脉冲磁场处理后再用nisin协同处理，枯草芽孢杆菌的内容物出现泄漏。

The effect of pulsed magnetic field (PMF) with the intensity of 3T and 30 pulses combined with temperature (50~100 ℃), ultrasonic (200 W, 5~30 min), and nisin (100~350 IU/mL) on the inactivation of Bacillus. subtilis (B.subtilis) was investigated. The results showed that after pretreated by PMF, the survival rate decreased with the increase of the temperature, ultrasonic power and the nisin concentration, and the lowest survival rate (3.17%) was achieved when B. subtilis were treated by PMF followed by the temperature at 100 ℃. The survival rate decreased with the the increase of treatment time by ultrasonic and the lowest survival rate of 8.18% was obtained when B. subtilis were treateded by PMF followed by ultrasonic at the power of 200 W with working time of 5 s and the interval of 10 s for 30 min. Increase in concentration of nisin led to the reduce of survival rate of B. subtilis. The combined treatments of PMF followed by nisin at 350 IU/mL exhibited a lowest survival rate of 19.21%. The inactivation effect was better when B. subtilis were treated by PMF followed by temperature, ultrasonic, and nisin than treated by temperature, ultrasonic, and nisin followed by PMF, which was in agreement with the phenomenon observed by the SEM. The morphology of B. subtilis changed and the cells shrunk after the combined treatments. The release of cytoplasmic contents of B. subtilis occurred after the treatments of PMF followed by nisin.

国家自然科学基金资助项目（31271966）；江苏省普通高校研究生科研创新计划（CX10B-021X）