^(60)Coγ射线辐照对耐辐射菌Deinococcus radiodurans蛋白质含量的影响

EFFECT OF ^(60)CO γ-RAYS IRRADIATION ON THE PROTEIN CONTENTSIN Deinococcus radiodurans

研究了耐辐射菌对60Coγ射线的辐射抗性,观察不同剂量照射后,细菌中蛋白质含量、辐照剂量及照射后培养不同时间的关系。应用平板菌落计数法,计数不同剂量辐照后的克隆数,计算存活率,绘制剂量—存活曲线。采用紫外分光光度法检测细菌中蛋白质的含量。结果表明, 耐辐射菌的存活曲线呈肩型,具有极强的辐射抗性。蛋白质的含量随着照射剂量的升高而不断增加,当辐射剂量达到5kGy时,蛋白质含量最高(p<0.01);若受照剂量>5kGy时,则蛋白质含量随受照射剂量的升高而逐渐降低。5kGy辐照后,随照射后温育时间的延长,蛋白质含量不断降低,培养时间为6h,蛋白质的含量最低(p<0.01),与对照组(未受照射组)相比,无显著性差异(p>0.05)。

In this paper, the radioresistance of bacterium Deinococcus radiodurans to 60Co γ-rays and the relationship between the protein content in the bacterium and the irradiation dose as well as the time after irradiation were studied. By counting the colonies on the plates which grew up from the irradiated and the control bacterium, the survival rate at each irradiation dose was calculated. The protein concentration was measured with the ultraviolet spectrophotometry. The results showed that the typical survival curve of Deinococcus radiodurans had a wide shoulder up to 5kGy, characterizing the radioresistance of the bacterium. The protein concentration increased with increasing dose, reaching the maximum at 5kGy. With time prolongation after 5kGy irradiation, the protein expressed in the bacterium reduced. And the lowest protein concentration, basically the same as the control, was observed 6h after the irradiation.