Bacillus subtilis TA1001 was used as the starting strain. By the treat of DES, ,the objective mutant TA208 ,which was adenine auxotrophy,the fastness of methionine sulfoxide(MSO)and 8-azaguanine (8-AG),was selected directionally.

• 以枯草芽孢杆菌TA1001为出发菌株,通过硫酸二乙酯(DES)及紫外诱变逐步诱变,定向选育出一株鸟苷产生菌TA208,其遗传标记为腺嘌呤缺陷、8-氮鸟嘌呤抗性和蛋氨酸亚砜抗性(Ade~-+8-AG~r+MSO~r)。