【摘要】 目的　以褐黄孢链霉菌 (Streptomyces gilvosporeus) S- 71为出发菌株 ,筛选纳他霉素的高产菌株。方法　紫外线对孢子悬浮液照射 4 0 s后 ,分别用链霉素抗性和琼脂块法进行筛选纳他霉素高产菌株 ,之后对高产菌株进行生产稳定性实验。结果　通过链霉素抗性法筛选获得了约 10 %的正选率突变株 ,其中突变株SG- 5 6摇瓶效价单位为 2 4 10μg/ ml,为出发菌株的 14 6 % ;通过琼脂块筛选法获得了约 1%的正选率突变株 ,其中突变株 SG- 2 0 0 2摇瓶效价单位为 2 6 5 0μg/ ml,为出发菌株的 16 1% ,该菌株无链霉素抗性标记。结论　链霉素抗性筛选和琼脂块筛选均可以获得纳他霉素的高产菌株 ,其中链霉素抗性筛选法效率高 ,琼脂块法筛选全面。更多还原

【Abstract】 Objective To obtain high natamycin-producing strain derived from Streptomyces gilvosporeus S-71. Method Screening high natamycin-producing strains by streptomycin-resistance method and agar block method after spore suspension was irradiated for 40 seconds. Subsequently the stability tests were performed. Results Ten percent of mutants increased the potency of natamycin by streptomycin-resistance method,including the mutant SG-56,which could produce natamycin 2410μg/ml that was 146% of potency of original strain by flask fermentation;about 1% of mutants increased the potency of natamycin by agar block method,including mutant SG-2002,which could produce natamycin 2650μg/ml that was 161% of potency of original strain by flask fermentation,but that mutant had not a sign of Str r. Conclusion The study indicated that high natamycin-producing strain could be obtained by both methods,and it had a high screening efficiency by streptomycin-resistance method and screening was completed by agar block method.更多还原