赤霉酸GA_(4+7)产生菌的诱变选育研究

Study on mutagenesis and breeding of GA_(4+7) producing strain

将GA_(4+7)产生菌制备菌丝悬液和原生质体悬液,用紫外照射叠加氯化锂诱变的方法进行迭代诱变,诱变处理后的菌液涂布平板,通过摇瓶培养筛选平板上的单菌落,最后得到一株突变菌GX34-4,相比出发菌株GA_(4+7),GX34-4的摇瓶效价提高约25%,50 L发酵罐效价提高约40%。与出发菌株的外观和效价不稳定性相比,突变株GX34-4遗传稳定性较好,连续传代5次,产量无明显降低,在50 L发酵罐上亦表现稳定。

The GA_(4+7)-producing strain was used to prepare mycelium suspension and protoplast suspension,and he iterative mutagenesis was carried out by ultraviolet irradiation and lithium chloride mutagenesis.The mutagenesisreated bacterial solution was coated on a plate,and the single colonies on the plate were screened by shaking bottle culture.Finally,strain GX34-4 was obtained.Compared to the starting strain GA_(4+7),the titer of GX34-4 in the shake flask was increased by about 25%,and the titer in the 50 L fermenter was increased by about 40%.The appearance and titer of the starting strain were unstable.The genetic stability of mutant GX34-4 was good,and the yield of mutant GX34-4 was not significantly reduced after five successive generations.which was also stable in a 50 L fermenter.