超声辐照对大肠杆菌和金黄色葡萄球菌的影响(英文)

EFFECTS OF ULTRASONIC IRRADIATION ON ESCHERICHIA COLI AND STAPHYLCOCCUS AUREUS

以革兰氏阴性细菌大肠杆菌和革兰氏阳性细菌金黄色葡萄球菌为研究对象,考察了超声条件对细菌灭活效果的影响以及相应的超声处理对细胞损伤、修复与细胞结构的影响,以衡量超声杀菌效率及随后的生物安全性问题.结果表明:超声条件增强,灭活效果提高;大肠杆菌对超声处理敏感,而金黄色葡萄球菌则有较大阻抗作用;超声处理对细胞没有显著的亚致死损伤,主要是直接致死;处理样在4℃低温保藏后活菌数皆下降,而在30℃保藏则略有提高;细胞内紫外吸收物质随着处理强度增大而漏出量增大,认为与细胞结构破损直接相关;电泳结果显示超声处理对胞内基因组DNA无明显影响.

Two microbes were chosen as the objects： Escherichia coli, a Gram-negative bacterium; and Staphylococcus aureus, a Gram-positive bacterium. To evaluate the efficiency of ultrasonic irradiation disinfection and the biological safety after treatment, besides the effects of ultrasonic irradiating parameters on the inactivation of microbes, the influences of ultrasonic treatment on cell injury, recover and cell structure were also investigated. The results showed that the inactivation improved as ultrasonic irradiation intensity increased. E.coli was susceptible to ultrasonic irradiation, but S. aureus was far more resistant to it than E.coli. There was no obvious sublethal damage on cells after treatment, and the injury effect of ultrasonic irradiation on cells was ＂all or nothing＂. Being stored at 4℃, the viable count of treated samples all reduced, but it slightly increased after being stored at 30℃. The leakage of intracellular UV-absorbant substances improved as the irradiation intensity increased, and it＇s thought to be related with cell structure collapse. The photograph of electrophoresis indicated that there＇s no obvious influence on genome DNA structure. As a conclusion, further researches about biological safety of ultrasonic irradiation disinfection is deserved to be continued.