基于单细胞光学技术探究微波和高温协同作用对微生物影响机制的研究

Study on the Synergistic Effect of Microwave and High Temperature on Microorganisms Based on Single Cell Optics

微波(300 MHz~30 GHz)对生物组织具有明显的热效应和生物效应,能极大程度上抑制微生物芽孢的生长,但从单分子层面研究微波和温度对干燥芽孢的影响机制鲜有报道。采用激光拉曼光镊技术(激光波长为532 nm,功率为2.5 mW),测量并对比不同温度下(50~125℃)微波处理(2450 MHz,150 W)芽孢的平均拉曼光谱,发现温度处于125℃时,1017 cm^(-1)峰强明显下降,表明高温和微波对芽孢内膜造成了损伤。该研究还使用原子力显微镜观察不同条件下芽孢的表面形貌特征,发现处理后的芽孢表面均有附着物,极有可能为CaDPA,温度越高现象越明显,而且随着温度的上升,芽孢的尺寸也随之下降,说明微波和高温的协同作用,导致芽孢核芯分子的泄露,同时也加剧了水分子蒸发使体积减小。该研究的结论为研究微波和温度协同作用对芽孢的影响提供了特征参数,也为应用单细胞光学技术开展理化因子对微生物影响机制的研究开拓思路。

Microwave(300MHz~30GHz)has obvious thermal and biological effects on biological tissues,and can inhibit the growth of microbial spores to a great extent.However,there are few reports on the mechanism of microwave and temperature effects on dried spores at the single-molecule level.In this paper,the laser Raman tweezers technology(laser wavelength is 532 nm,power is 2.5mW)was used to measure and compare the average Raman spectra of spores treated by microwave(2450 MHz,150W)at different temperatures(50~125℃).It was found that the peak intensity of 1017cm^(-1)decreased significantly at 125℃.It showed that high temperature and microwave caused damage to the intima of spores.In this study,atomic force microscopy was also used to observe the surface morphological characteristics of spores under different conditions,and it was found that there were attachments on the surface of treated spores,most likely CaDPA.The higher the temperature was,the more obvious the phenomenon was,and the size of spores also decreased with the increase of temperature,indicating that the synergistic effect of microwave and high temperature led to the leakage of core molecules of spores.It also increases the evaporation of water molecules and reduces the volume.The conclusion of this study provides characteristic parameters for studying the synergistic effect of microwave and temperature on spores,and also opens up ideas for studying the effect mechanism of physical and chemical factors on microorganisms by using single cell optics technology.