微波加热对大肠杆菌与金黄色葡萄球菌蛋白质与核酸变性的影响  

The effect of microwave heating on the denaturation of E.coli and S.aureus intracelluar protein and nucleic acid

作　　者：杭锋[1,2] 陈卫[2] 陈帅[1,2] 龚广予[1] 王荫榆[1] 张灏[2] 郭本恒[1] 

机构地区：[1]光明乳业股份有限公司技术中心,上海200072 [2]江南大学食品学院食品科学与技术国家重点实验室,江苏无锡214122

出　　处：《食品与机械》2008年第5期12-15,共4页Food and Machinery

基　　金：国家自然科学基金重点资助项目(项目编号:20436020)

摘　　要：研究微波杀菌过程中蛋白质与核酸的变性程度及其与微生物致死率之间的关系,测定了微波加热过程中大肠杆菌与金黄色葡萄球菌的蛋白质与核酸的"内源荧光"及残存菌数的变化。试验结果表明,当温度升高至50,55℃,大肠杆菌与金黄色葡萄球菌蛋白质和核酸"内源荧光"强度以及致死率均未发生明显变化;当温度升高至60℃时,大肠杆菌胞内蛋白质和核酸的"内源荧光"强度以及致死率分别增加了44.4%,41.8%,33%,而此时,金黄色葡萄球菌分别增加了8.7%,9.0%,12%;当温度升高至65℃时,大肠杆菌增加程度分别为71.3%,70.2%,65%,金黄色葡萄球菌变化程度分别为9.0%,10.6%,23%。随着微波加热温度的升高,大肠杆菌与金黄色葡萄球菌的蛋白质与核酸的"内源荧光"强度变化且与致死率呈正相关,因此,胞内蛋白质与核酸变性是微生物微波致死的因素之一。Microwave heating could induce the denaturation of intracellular protein and nucleic acrid, which led microorganisms to death. The intrinsic fluorescence of intracellular protein and nucleic acid and viable counts after microwave heating treatment were measured, in order to establish the relationship between the denaturation degrees of intraceltular protein and nucleic acid and the inactivation rates for E. eoli and S. aureus. The results showed that, with the temperature in cell suspension rising, the denaturation degrees of protein and nucleic acid and the inactivation rates enhanced. At 50, 55 ℃, there were no significant changes of denaturation and inactivation rates for both E. coli and S. aureus. When the temperature reached 60 ℃, the rates of protein denaturation, nucleic acid denaturation and death were 44.4% , 41. 8% and 33% in E. coli, and 8.7%, 9.0% and 12% in S. aureus respectively. When the temperature reached 65 ℃, the rates were 71.3% ,70.2% and 65% in E. coli, and 9.0%, 10.6% and 12% in S. aureus, denaturation degrees were just 8.7%, 9.0% respectively. So, the denaturation of intracellular protein and nucleic acid were one of the inactivation mechanisms of microwave heating.

关 键 词：大肠杆菌 金黄色葡萄球菌 微波杀菌 变性 内源荧光 

分 类 号：Q93[生物学—微生物学]