荧光偏振法研究脉冲电场对酿酒酵母细胞膜流动性影响  

Fluorescence Polarization Used to Investigate the Cell Membrane Fluidity of Saccharomyces Cerevisiae Treated by Pulsed Electric Field

作　　者：张鹰[1] 曾新安[1] 温其标[1] 李琳[1] 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640

出　　处：《光谱学与光谱分析》2008年第1期156-160,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金重点项目(20436020);广东省自然科学基金(04020063)资助

摘　　要：以DPH(1,6-二苯基-1,3,5-己三烯)为荧光探剂,采用荧光偏振法探讨了脉冲电场(0～25kV.cm-1,0～266ms)对酿酒酵母细胞膜流动性影响。经5kV.cm-1电场处理后,酿酒酵母细胞膜的流动性显著减小,并且随电场强度和处理时间的增加而减小;通过平板计数法和紫外分光光度计法分别检测了脉冲电场对酿酒酵母细胞存活对数及膜通透性影响。结果显示,5kV.cm-1虽然只能使少量的酵母致死,却能使酵母细胞膜的通透性显著增加,膜流动性显著降低。并且细胞的存活率随电场强度增大而减小,细胞膜的通透性随电场强度增大而增大。这表明细胞膜的流动性降低与细胞膜的通透性升高成正相关,与细胞的存活率成负相关。由此推测脉冲电场在对酿酒酵母灭菌过程中,细胞膜是其作用的一个关键位点,膜流动性减小,细胞膜通透性增强,是细胞死亡的主要原因。To know the lethal mechanism of microorganisms under pulsed electric field treatment, the relationship between the inactivation of Saccharomyces cerevisiae （CICC1308） cell and the permeability and fluidity changes of its cell membrane treated by pulsed electric field （0-25 kV·cm^-1, 0-266 ms） was investigated. With 1,6-diphenyl-1,3,5-hexatriene （DPH） used as a probe, the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field was expressed by fluorescence polarization. Results showed that the cell membrane fluidity decreases when the electric flied strength is up to 5 kV·cm^-1, and decreases with the increase in electric field strength and treatment time. The plate counting method and ultraviolet spectrophotometer were used to determine the cell viability and to investigate the cell membrane permeability, respectively, treated by pulsed electric field. Results showed that the lethal ratio and the content of protein and nucleic acid leaked from intracellular plasma increased with the increase in the electric field strength and the extension of treatment time. Even in a quite lower electric field of 5 kV·cm^-1 with a tiny microorganism lethal level, the increase in UV absorption value and the decrease in fluidity were significant. It was demonstrated that the cell membrane fluidity decreases with the increase in lethal ratio and cell membrane permeability. The viscosity of cell membrane increases with the decrease in fluidity. These phenomena indicated that cell membrane is one of the most key sites during the pulsed electric field treatment, and the increased membrane permeability and the decreased cell membrane fluidity contribute to the cell death.

关 键 词：荧光偏振法 脉冲电场 细胞膜流动性 

分 类 号：Q64[生物学—生物物理学]