Study on the Agricultural Antibiotics 702 Producing Mutant of Streptomyces 702 by NTG Mutation

Objective:To screen out a Streptomyces 702 strain of high yield of antifungal substance.Method: Gentamycin-resistance mutational labelling selection model with Streptomyces 702 strain as experiment material and Gentamycin as sensitive antibiotic was built to screening high-yield mutants.The Streptomyces 702 spores was treated by NTG.Result:The gentamycin-resistance mutational frequency of the Streptomyces 702 treated by NTG with 90 minutes was up to 23.64% and the lethal rate was 73.46%.High antifungi substance-producing mutant 20-29-12 was isolated in the screening experiments,and its yield of antifungi substance reached 1443μg/mL,which was 38.08% higher than that produced by its parent strain.Conclusion: The Streptomyces 702 strain of high antifungal substance could be obtained by NTG mutation and resistance-chemical mutational labelling selection model.