枯草芽孢杆菌淀粉酶高产菌株的辐射诱变研究  

The studies on radiation mutation breeding of Bacillus subtilis with high-yield of amylase

作　　者：陈晓明[1] 张良[2] 张建国[2] 周莉薇[2] 

机构地区：[1]西南科技大学生命科学与工程学院,绵阳621010 [2]西南科技大学核废物与环境安全国防重点学科实验室,绵阳621010

出　　处：《辐射研究与辐射工艺学报》2008年第3期177-182,共6页Journal of Radiation Research and Radiation Processing

基　　金：中国工程物理研究院预研项目(052056);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);中国物理研究院核物理与化学研究所项目资金资助

摘　　要：采用了不同总辐照剂量和剂量率的γ射线以及快中子一次、二次辐照枯草芽孢杆菌,采用平板透明圈方法,以菌落直径、透明圈直径、透明圈直径与菌落直径之比(HC值)为指标,研究γ和快中子辐照对枯草芽孢杆菌产淀粉酶的辐射诱变效应,同时筛选高产淀粉酶的变异株。结果表明:(1)快中子和γ射线都能有效诱导枯草芽孢杆菌高产淀粉酶;(2)采用不同总辐照剂量和剂量率的γ射线和快中子一次辐照后,菌落平均直径均比对照小,且随着γ射线辐照剂量的增大,菌落平均直径有变小的趋势;(3)采用快中子二次辐照后,菌落平均直径、菌落最大直径、透明圈平均直径、透明圈最大直径以及HC最大值都远远高于原菌落值;(4)重复筛选出三株高产淀粉酶菌株,它们的菌落直径最大为8.32mm,透明圈直径最大为22.38mm,透明圈与菌落直径之比最大达到5.39。且有两株在传至15代都能稳定高产淀粉酶。The mutagenesis effects on the yield of amylase have been investigated with Bacillus subtilis irradiated by γ-rays and fast neutrons in once or twice irradiation at various dose rates and total irradiation doses. Several parameters such as flat transparent circle, colony diameter, transparent circle diameter and the ratio of flat transparent circle to colony diameter （HC） are used to estimate the radiation mutation of Bacillus subtilis. A series of results has been obtained as （1） Irradiation both with neutrons and γ-rays could make Bacillus subtilis mutationed to produce high-yield amylase effectively. （2） The average colony diameter of Bacillus subtilis irradiated by γ-rays or fast neu- trons is smaller than that of control group at various total doses and dose rates. And their colony diameter becomes smaller slightly with the increment of γ-rays irradiation dose. （3） After the second neutrons irradiation, the values of average colony diameter, the biggest colony diameter, average transparent circle diameter and the biggest transparent circle diameter of all mutationed Bacillus subtilis exceed that of original strains greatly. （4） Three kinds of mutationed Bacillus subtilis strains with high-yield amylase have been screened out, in which two strains can produce high-yield amylase steadily after 15 times breeding. Their biggest colony diameter, the biggest transparent circle diameter and the biggest HC value are up to 8.32 mm, 22.38 mm and 5.39 respectively.

关 键 词：中子辐照 Γ射线 辐射诱变育种 淀粉酶 

分 类 号：Q93[生物学—微生物学] Q939.99