59 was treated with DES. A streptomycin-resistant mutant S-71 was obtained by streptomycin resistance screening. The natamycin yield of S-71 was up to 1.64g/L.

• 首先利用硫酸二乙酯进行化学诱变，结合链霉素抗性筛选，获得纳他霉素产量达到1.；64g/L的诱变菌株S-71。