The strain A-49 was chosen as the start strain for mutagenic treatments with ultraviolet irradiation + LiCl, DES and Streptomycin resistant rational screening, after first and second selection, the mutant S-22 was selected.

• 以菌株A-49为出发菌株，依次用紫外线氯化锂复合诱变、硫酸二乙酯诱变、链霉素抗性诱变等多种诱变手段对菌株A-49进行育种工作。