Furuta M, Yamaguchi M, Tsukamoto T, Yim B, Stavarache C E, Hasiba K, Maeda Y
Research Institute for Advanced Science and Technology, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 599-8570, Japan.
Ultrason Sonochem. 2004 Apr;11(2):57-60. doi: 10.1016/S1350-4177(03)00136-6.
Ultrasonic inactivation of Escherichia coli XL1-Blue has been investigated by high-intensity ultrasonic waves from horn type sonicator (27.5 kHz) utilizing the "squeeze-film effect". The amplitude of the vibration face contacting the sample solution was used as an indication of the ultrasonic power intensity. The inactivation of the E. coli cells by ultrasonic irradiation shows pseudo first-order behavior. The inactivation rate constant gradually increased with increasing amplitude of the vibration face and showed rapid increase above 3 microm (p-p). In contrast, the H2O2 formation was not observed below 3 microm (p-p), indicating that the ultrasonic shock wave might be more important than indirect effect of OH radicals formed by ultrasonic cavitation in this system. The optimal thickness of the squeeze film was determined as 2 mm for the E. coli inactivation. More than 99% of E. coli cells was inactivated within 180-s sonication at the amplitude of 3 microm (p-p) and 2 mm of the thickness of the squeeze film.
利用“挤压膜效应”，通过喇叭型超声处理器（27.5 kHz）产生的高强度超声波研究了大肠杆菌XL1-Blue的超声失活情况。将接触样品溶液的振动面的振幅用作超声功率强度的指标。超声辐照对大肠杆菌细胞的失活表现出假一级动力学行为。失活速率常数随着振动面振幅的增加而逐渐增大，在3微米（峰-峰值）以上呈现快速增加。相反，在3微米（峰-峰值）以下未观察到过氧化氢的形成，这表明在该系统中超声冲击波可能比超声空化形成的羟基自由基的间接效应更重要。确定挤压膜的最佳厚度为2毫米以实现大肠杆菌的失活。在3微米（峰-峰值）的振幅和2毫米的挤压膜厚度下，超声处理180秒内超过99%的大肠杆菌细胞被灭活。
