超声处理对酵母细胞的致死及相关影响

超声处理作为新兴的非热杀菌技术,由于对超声处理条件的作用规律和对微生物细胞的影响研究不足,在实际应用中还不成熟.文中以酿酒酵母为对象,考察超声杀菌处理效果的三个主要影响因素(即超声功率、时间和脉冲占空比)对细胞致死作用的影响规律,并采用选择性平板法对超声引起的细胞亚致死效应进行检测,采用TEM对细胞超微结构变化进行检测.结果表明:超声功率及时间对细胞的致死作用影响显著;超声处理后细胞未检出显著的亚致死损伤;超声处理对细胞的超微结构破坏大,表明结构完整性的破坏可能是细胞死亡的直接原因.

Inactivation of Yeast Cells by Ultrasound Disinfection and Related Influences

As an emerging nonthermal disinfection technique,ultrasonic treatment is still in its infancy of industrial application due to the insufficient investigations into its influencing rules on disinfection and its effects on cells.In order to solve this problem,Saccharomyces cerevisiae was chosen as the object to reveal the effects of three ultrasonic parameters on the inactivation of yeast cells.The parameters included the ulrasonic power,the irradiation time and the pulse ratio.Moreover,the selective medium method and the TEM were adopted to investigate the cell sublethal injury caused by ultrasonic treatment and the cell ultramicrostructure after the treatment,respectively.The results show that(1) both the ultrasonic power and the irradiation time have significant positive effects on the inactivation of cells;(2) no sublethal injured cells are detected after the ultrasonic treatment;and(3) ultrasonic irradiation may result in great damage to cell ultramicrostructure.It is thus concluded that the damage of structural integrity could be the direct reason for the death of cells.