摘要
以市场上常见的4种用于制作纳豆食品的菌粉(菌液)为出发菌,采用2种不同诱变剂(紫外线和亚硝基胍)在不同剂量下复合诱变处理,试验结果表明,原始菌株在紫外线照射时间为80 s、NTG剂量为0.4 mg/m L时,致死率分别为83%和87%。以此诱变条件对纳豆芽孢杆菌进行紫外线、NTG复合诱变,通过与指示菌共同涂布培养,以菌体的生长情况、菌落直径的大小以及抑菌圈直径为初筛标准,初筛出了60株抑菌效果较好的菌株。进一步通过管碟法复筛,得到1株具有较高抗菌活性的突变株L-23,抑菌圈直径可达27 mm,传代培养10次后抑菌圈直径无显著变化,其抑菌活性具有较好的遗传稳定性。
In this study,four strains of Bacillus natto were separated and purificated from the natto powders.In order to improve the antibacterial substance production, the four strains was irradiated by UV and NTG.The results showed that when Bacillus natto be irradiated by UV for 80 s or be treated by 0.4 mg/mL NTG,the lethality rates were 83% and 87% respectively.After treatment with compound mutation,60 stains was screened out according to the growth rate of bacteria,diameter of colonies and inhibitted bacteria eircles.Mter secondary screening with slip method and cylinderplate method, a mutant strain （L-23）was selected, which can generate a 27 mm inhibitted bacteria circles and it has a good stability in generation.
出处
《现代农业科技》
2016年第17期251-252,255,共3页
Modern Agricultural Science and Technology
关键词
纳豆芽孢杆菌
抑菌
诱变
筛选
bacillus natto
antibacterial
mutation
screen
