Induced breeding of high producing strains of natamycin from Streptomyces gilvosporeus

In order to improve the yield of natamycin,the original strain Streptomyces gilvosporeus-17 was treated with the cooperation of UV,microwave and Co60-γ rays.According to the interaction of lethal rate and radiation dose,the optimum dose was determined.A mutant strain was obtained by induced breeding of strain SG-17,which was treated with 80 s UV,50 s microwave and following 1.5 kGy γ-rays.The natamycin yield of γ-188 was 4.58 g/L,which was higher than that of strain SG-17.The cooperative effect of UV,microwave and γ-rays was perfect.The result of this experiment showed that the mutant strain was stable and high natamycin yield.