磁场处理对酿酒酵母微观结构及细胞膜流动性的影响及作用机理.

摘要：以磁场为外加物理场，采用恒定磁场及循环磁处理方式对酿酒酵母进行磁处理，研究酿酒酵母微观结构及细胞膜流动性的变化。通过透射电子显微镜，观察不同磁感应强度恒定磁场处理后酿酒酵母的微观结构，发现恒定磁场可以促进酵母细胞的生长，群体中以具有中央大液泡为特征的成熟细胞所占比率增大，同时线粒体呈现适应性膨大、增生。以原子力显微镜观察循环磁处理下酵母细胞的三维结构，发现细胞壁表面出现皱缩、穿孔，胞质外流，证实循环磁处理具有脉冲磁场的特征，可产生瞬间高能作用于细胞，从而产生致死效果。用荧光偏振法对两种处理方式下细胞的膜脂流动性进行测定，发现不同强度恒定磁场处理后，膜脂各向异性下降，流动性增强，0.05T磁感应强度下各向异性值下降3.57%，而循环磁处理后各向异性值比对照提高了8.46%，膜脂流动减慢，证实细胞膜为磁场作用的一个靶点。

Effect and Mechanism of Magnetic Fields Treatment on Microscopic Structure and Cell Membrane Fluidity of Saccharomyces cerevisiae.

Abstract: The magnetic fields was taken as the external physical fields to treat Saccharomyces cerevisiae with two different modes, static magnetic fields(SMF) treatment and magnetic cycling treatment, to study the changes of microscopic structure and cell membrane fluidity of S.crervisiae. The microscopic structure of cells treated by SMF of different magnetic flux intensities was observed by using transmission electron microscopy (TEM). The results showed that the SMF could stimulate the growth of S.cerevisiae cells, the ratio of mature cells with large central vacuoles in the colony increased. Swell and hyperplasia of mitochondria were also observed after the stimuli for their adaptability. Atomic force microscopy (AFM) micrographs exhibited three dimensional structures of yeast cells treated in cycle with magnetic fields. It was found the surface of cell wall wrinkled, magnetoporation appeared, and the cytosol leaked. The fluidity of cell membrane was determined by fluorescence polarization technique. All magnetic flux intensities of SMF caused the increase of membrane fluidity; r-value decreased 3.57% at the level of 0.05T treatment. Whereas with the magnetic cycling treatment, r-value enhanced 8.46%, the fluidity decreased. It proved that the cell membrane was a target site in magnetic treatment.