产类细菌素乳酸乳球菌V528的紫外线诱变育种研究

目的获取高产抑制鸡白痢沙门菌生长的类细菌素乳酸乳球菌的突变菌株。方法在紫外线照射致死率为82.7%的剂量下,对处于对数生长后期的乳酸乳球菌V528进行紫外线二次复合诱变处理。分别随机对第一次和第二次复合处理后生长的117株和310株菌进行效价测定分析。结果在实验所用的照射剂量下,抑菌效价提高的正突变菌株占有一定优势,负突变菌株较少,其中突变菌株Lact.174的抑菌效价较V528的效价提高了8.48倍,并具有一定的遗传稳定性。结论运用紫外诱变育种技术可有效地获得高产类细菌素的突变菌株。

Studies on UV mutational breeding of Lactococcus lactis V528 for producing bacteriocin-like substance

Objective To select mutants with high productivity of anti-Salmonella pullorum bacteriocin-like substance.Methods The cells of Lactococcus lactis V528,in the late exponential phase,were mutated by ultraviolet radiation with 82.7% death rate.The colonies of 117 and 310 were seleted for testing the antibacterial titer of the culture supernatant,after radiated by the first time and sencond time respectively.Results Under this condition,the numbers of positive mutants had some content predominance over negative ones.And among them,the bacteriocin-like substance yield of strain Lact.174 was 8.48 times more than the original strain with stable inheritance.Conclusion Mutants with high productivity of bacteriocin-like substance were got efficiently by UV mutational breeding.