微波场对微生物DNA的作用研究

目的研究微波场对微生物DNA的作用,了解微波杀菌机理。方法用免疫电泳法和基因扩增法对经微波照射处理悬液内指标菌DNA进行检测,观察其损伤情况,并与普通煮沸加热法作平行比较。结果经微波加热沸腾和非沸腾状态处理的微生物,总DNA条带出现弥散或缺失。微波场铜网屏蔽和煮沸加热处理的微生物,总DNA条带无缺失现象。微波场照射处理枯草芽孢杆菌黑色变种和大肠杆菌,在温度升至72℃时,非连续处理后DNA条带无损伤现象;在温度上升到85℃时,非连续处理后DNA条带明显减弱。结论微波场对微生物DNA有损伤作用,温度升高或作用时间延长微波对微生物DNA的破坏作用增加,提示微波场对微生物的作用存在非热效应,也存在热效应。

STUDY ON EFFECT OF MICROWAVE ON DEOXYRIBONUCLEIC ACID OF MICROORGANISM

Objective To study the effect of microwave on total DNA of microorganism,and to know the germicidal mechanism of microwave.Methods Immunoelectrophoresis and gene amplification method were used to examine bacterial DNA in suspension irradiated by microwave,to observe its injuries,and to make parallel comparison with ordinary boiling heating.Results After the bacteria were treated with microwave boiling and unboiling heating radiation,the total DNA band of bacteria was obviously absent or dispersed,but this phenomenon was not observed after treatment with microwave shielded by brass grid and boiling heating in water bath.When Bacillus subtilis var.niger and Escherichia coli were treated with microwave irradiation and the temperature rose to 72℃,there was no damage of DNA band after non-continuous treatment;but when the temperature rose to 85℃,there was obvious weakening of the DNA band after non-continuous treatment.Conclusions Microwave can break the DNA chain of microorganism,and the damage of DNA by microwave increased with increasing temperature and extending the irradiation time,indicating that there are both non-thermal effect and thermal effect.