重离子束辐照选育高产细菌素植物乳杆菌

采用重离子束12C6+对产细菌素植物乳杆菌Lp1进行辐照选育，分析比较了不同辐照剂量下致死率和突变率，并通过双层琼脂扩散法筛选高产细菌素突变菌株。在辐照剂量300 Gy时，出发菌株植物乳杆菌Lp1的致死率和正突变率分别为86.3%和28.28%。在300 Gy辐照菌悬液中，分离筛选出高产细菌素突变菌株Lp092、Lp085，以大肠埃希氏菌为指示菌抑菌圈直径比出发菌株Lp1分别扩大了20.64%、19.36%，以金黄色葡萄球菌为指示菌抑菌圈直径比出发菌株Lp1分别扩大了17.16%、14.14%，经过连续传代5次实验，2株菌株Lp092、Lp085均具有良好的产细菌素遗传稳定性。

Study on Mutation Breeding of High-Yield Bacteriocin Lactobacillus plantarum by Heavy Ion Beam Irradiation

The heavy ion beam of 12C6+ was used to irradiate the original strain Lactobacillus plantarum Lp1 of bacteriocin-producing. The lethality and mutation rate of theoriginal strain Lp1 at different irradiation doses were analyzed and compared, and the mutant strains with high bacteriocin production were screened by double layer agar diffusion method. At the irradiation dose of 300 Gy, the lethality rate and positive mutation rate of the original strain Lp1 were 86.3% and 28.28%, respectively.In the 300 Gy irradiation bacterial suspension, mutant strains Lp092 and Lp085 with high bacteriocin production were isolated and screened, the diameters of inhibition zones of Escherichia coli as the indicator bacteria were increased by 20.64%, 19.36%, the diameters of inhibition zones of staphylococcus aureus as the indicator bacteria were increased by 17.16%, 14.14% than the original strain Lp1, respectively.After 5 times successive generations, 2 strains Lp092 and Lp085 have good genetic stability for bacteriocin production.