上游充通大学 Shanghai Jiao Tong University I.Physical Antimicrobial Control 6.1 Heat Sterilization 6.2 Radiation Sterilization 6.3 Filter Sterilization Shanghai Jiao Tong University
Shanghai Jiao Tong University I. Physical Antimicrobial Control 6.1 Heat Sterilization 6.2 Radiation Sterilization 6.3 Filter Sterilization
上泽充通大￥ Shanghai Jiao Tong University 6.1 Heat sterilization热力杀菌 High temperatures can influence growth Denaturation at high temperature:the lose of structure and ability to function of macromolecules高温使大分子变性 Proteins are the most heat sensitive macromolecules.Its higher order structures will be effected first蛋白质对热最 不稳定，其高级结构最先改变 Shanghai Jiao Tong University
Shanghai Jiao Tong University 6.1 Heat sterilization 热力杀菌 High temperatures can influence growth • Denaturation at high temperature: the lose of structure and ability to function of macromolecules 高温使大分子变性 • Proteins are the most heat sensitive macromolecules. Its higher order structures will be effected first蛋白质对热最 不稳定, 其高级结构最先改变
上泽充通大￥ Shanghai Jiao Tong University Heat sterilization is the most widely used method of controlling microbial growth High temperatures denature macromolecules Some bacteria produce resistant cells called endospores Can survive heat that would rapidly kill vegetative cells Shanghai Jiao Tong University
Shanghai Jiao Tong University Heat sterilization is the most widely used method of controlling microbial growth • High temperatures denature macromolecules Some bacteria produce resistant cells called endospores • Can survive heat that would rapidly kill vegetative cells
上泽充通大￥ Shanghai Jiao Tong University 6.11 Kinetics of heat sterilization Death from heating is an exponential.热致死是指 数形式的 The higher the temperature,the quicker the killing The time taken for a definite fraction(for example, 90%)of the cells to be killed is independent of the initial concentration.杀死指定比例（如90%）的微 生物所需时间与最初的微生物浓度无关 Shanghai Jiao Tong University
Shanghai Jiao Tong University 6.1.1 Kinetics of heat sterilization Death from heating is an exponential. 热致死是指 数形式的. • The higher the temperature, the quicker the killing The time taken for a definite fraction (for example, 90%) of the cells to be killed is independent of the initial concentration.杀死指定比例(如90%)的微 生物所需时间与最初的微生物浓度无关
上降充通大￥ Shanghai Jiao Tong University Important term of heat sterilization decimal reduction time(D)十倍致死时间 The time required for a ten fold reduction in the population density at a given temperature Determination of D:Viable counting Shanghai Jiao Tong University
Shanghai Jiao Tong University decimal reduction time (D)十倍致死时间 • The time required for a ten fold reduction in the population density at a given temperature • Determination of D: Viable counting Important term of heat sterilization