摘要
以研究辐射灭菌的生物安全性为目的,考察不同辐照源、辐照剂量及辐照方式下枯草芽孢杆菌辐射耐受性以及毒性的变化情况。从经不同剂量1次中子辐照后的存活平板中随机挑取菌落,扩大培养后再次进行低、中、高剂量的2次中子和γ射线辐照。结果发现,经中子1次辐照后,芽孢对2次中子辐照产生耐受性和敏感性的可能同时存在,但以敏感性为主,仅发现1个菌落对低剂量2次中子辐照产生耐受性;而对γ射线2次辐照均表现为敏感性。中子1次辐照的剂量对中子和γ射线2次辐照的灭菌效应并没有发现明显的影响。这说明中子1次辐照后,能显著提高中子和γ射线2次辐照杀死芽孢的能力。从接受了中子和γ射线照射后的菌落中,筛选出7株酶活性较高的变异菌株,采用小白鼠腹腔注射方法,考察这些菌株的毒性。通过对小白鼠的增重率、肝脏系数、脾脏系数等指标的分析,发现不同剂量的中子1次辐照、中子2次辐照和不同剂量的γ射线辐照,对枯草芽孢杆菌的毒性都没有明显的影响。这初步说明中子和γ射线辐照枯草芽孢杆菌就生物辐照耐受性和毒性来说是安全的。
This paper is aimed to report our investigation results of the radicidation bio-safety of the residual bacteria after neutron and T- ray radiation extinction along with the influence of radiation types, dosages and modes on the Bacillus subtilis radiation tolerance and toxicity. The colonies we have chosen randomly from the survivors after various neutron radiations in different dosages. The colonies cultured can then be radiated again by using low-, medium-, and high- dosage neutron and T radiation respectively. The spores we have gained then indicate beth of their properties of tolerance and sensitiv ty to neutron reirradiation by giving the priority to their radio-sensitivity. However, there is only one single kind of colony which is tolerable to neutron reirradiation. But the spores here only represent the sensitivity to γ reirradiation. Such results of our experiments just show that the neutron and γ radicidation strength can be enhanced by the first neutron radiation whereas the seven mutational Bacillus subtilis strains with high-yield enzyme can just be screened out from the survivor after neutron and γ radiation. Such strains＇ toxicity were later analyzed by injecting rat abdomen, with some indexes, such as the rate of liver weight growth, liver coefficient and spleen coefficient, being used to test the toxicity of the radiated spores. Nevertheless, such indexes of the radiated spores turn out not to make any evident change as compared to the control group. Therefore, the results of our preliminarily study indicate neutron and γ radiation Bacillus subtilis are safe in the field of radiation tolerance and toxicity. However, due to the limited sample amount for such a big research topic, the conclusion doesn＇t seem sound and comprehensive enough, which makes it necessary for further experimental investigations before arriving at persuasive conclusions.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2009年第5期1-4,共4页
Journal of Safety and Environment
基金
中国工程物理研究院科学技术发展基金项目(2008A0103002)
西南科技大学核废物与环境安全国防重点学科实验室基金项目(07JGZB07)
关键词
环境生物学
辐射耐受性
辐射敏感性
毒性
2次辐照
environmental biology
radiation tolerance
radiosensitivity
toxicity
reirradiation
