低能N^+注入选育凝结芽孢杆菌高效生防菌株

Mutation Breeding of High-efficiency Biocontrol Strain of Bacillus coagulans by Low Energy N^+ Ion Beam Implantation

为了进一步提高凝结芽孢杆菌NJYHHWG 877005菌株的拮抗性能,获得生防效果更好的菌株,利用低能N^+注入菌株进行诱变,并通过平板对峙培养对诱变处理后的菌株进行筛选。结果表明,菌株存活率曲线遵循N^+注入生物效应的马鞍型曲线,根据其存活率及突变率确定N^+最佳注入能量为15 ke V,最佳注入剂量为140×10^(13)个/cm^2。通过筛选获得1株具有良好性状的突变株L1,芽孢形成率达77.42%,对灰葡萄孢霉菌的抑制率高达87.81%,分别较原始出发菌株提高了23.79、11.71个百分点,且连续传代培养8次,遗传稳定性良好。

In order to improve the antagonistic ability of Bacillus coagulans NJYHHWG 877005 and search for high-efficient mutant strains,the strain was induced by low energy N~＋ion beam implantation and the mutation strains were screened by confrontation experiments. It was found that the curve of survival took a ＂saddle shape＂with N~＋ion dose increased. By the livability and mutation rate of the strain,the best induced mutation action was decided when the used energy and ions implantation dose were 15 ke V and 140 × 10^（13）N~＋/ cm^2. A fine strain L1 was obtained through screening. The forming rate of spore was up to 77. 42%,and the inhibition rate of the mutant strain against Botrytis cinerea was up to 87. 81%,increased by 23. 79 and 11. 71 percentage points compared to the primitive strain,respectively. After eight generations of propagation,the mutant strain showed high genetic stability.