摘要
以A6-1为出发菌株,采用N+离子注入的方法进行诱变处理,注入能量为50keV,注入剂量为1×1013、3×1013、5×1013、8×1013、10×1013、30×1013、50×1013、80×1013、100×1013ion/cm2,真空度为10-3Pa。结果显示,菌体的存活率随离子注入剂量的增加呈"马鞍型"曲线,"鞍脊"出现在30×1013ions/cm2～50×1013ions/cm2之间,此时菌体的存活率在20%～35%之间。综合考虑存活率、总突变率、正突变率和突变幅度等因素,推荐30×1013ions/cm2作为离子注入植物乳杆菌的适宜诱变剂量。从所有的注入处理中挑选CLA转化能力提高了50%以上的突变株进行传代稳定性试验,发现F菌株经8次传代后产CLA的稳定性最好。该突变株各代的产量平均为162.5μg/ml,比出发菌株提高了69.87%,将此突变菌株命名为A6-1F。
The initial lactic acid bacteria strain A6-1 was treated by N^＋ ions implantation of 50 keV with doses of 1×10^13 , 3×10^13 , 5×10^13 , 8×10^13 , 10×10^13 , 30×10^13 , 50×10^13 , 80×10^13 , and 100×10^13 ions/cm^2. The survival curve showed a saddle model, and the high survival rate was 20%～35% from the treatments of 30×10^13 ions/cm^2 and 50×10^13 ions/cm^2 implantation. Considering the survival rate, positive mutation and range of mutation rate, N^＋ ions implantation of 30×10^13 ions/cm^2 was recommended for mutation breeding of lactic acid bacteria. Selected mutants with high ability of producing CLA after fermentation. Generic stable was observed until 8 generations of F mutant, and average yield of CLA was 162.5 μg/ml, which was 69.87% higher than the original stain. F mutant was named A6-1F.
出处
《核农学报》
CAS
CSCD
北大核心
2009年第5期794-798,共5页
Journal of Nuclear Agricultural Sciences
基金
863项目No.2006AA10Z345
