摘要
为探讨脉冲电场(PEF)致死微生物的机理,研究了不同场强与处理时间对悬浮在温度为30°C,电导率σ为340μS/cm的NaCl溶液中大肠杆菌的灭菌效果。紫外分光光度计分析PEF处理前后核酸与蛋白质的溢出情况的结果显示,电场强度为30 kV/cm,处理时间266 ms时,大肠杆菌全部杀灭。经PEF处理后的大肠杆菌液中的核酸与蛋白质相对于未处理的大肠杆菌液有明显提高,说明用PEF处理提高了细胞膜的通透性。采用ERIC-PCR技术比较脉冲电场处理前后大肠杆菌的DNA指纹图谱变化的结果表明:强PEF(场强≥20kV/cm)导致大肠杆菌的DNA链损伤与降解,在指纹图谱上表现为DNA大分子条带的缺失与小分子量条带的增加。
This paper studies the effects of different electric field strength and treatment time on the inactivation of E coli suspended in sodium chloride（electric conductivity δ= 340μS/cm, 30 ℃） by a continuous high intensity pulsed electric field （PEF） treatment system. The plate counting method is used to determine the viability of the cells. The results show that the survival of E coli decreases with increasing the electric field strength and treatment time, and E. coli is inactivated by 30 kV/cm, 266 ms treatment. The subsequent leakage of protein and nucleic acid of E coli due to the PEF processing is investigated by using the ultraviolet spectrophotometric method. And the relative amounts of the leaked protein and nucleic acid from E coli increase after the PEF treatment, and increase with increasing the electric field strength and treatment time, showing that PEF treatment increases the membrane permeabilization of E coil ERIC（Enterbacteria Repetitive Intergenic Consensus ）-PCR method is used to determine the inactivation of PEF on E coil ERIC-PCR fingerprinting demonstrated that DNA of the treated E coli is injured and DNA degradation appeares when the electric field strength is up to 20 kV/cm for 539 ms or more severe PEF treatment（ 30 kV/cm for 266 ms;35 kV/cm for 266 ms; 50 kV/cm for177 ms）, and macromolecule DNA is degraded into small molecule fragments. The results indicate the increased membrane permeability and DAN degradation may resulted in the lethal of E coli .
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2007年第2期90-93,共4页
High Voltage Engineering
基金
广东省自然科学基金资助项目(04020063)
