UV-LiCl Complex Mutation for Breeding Superior Strain of Tiamulin

Irradiated by ultraviolet(UV) for 180 s,bacterial suspension of Streptomyces strain TMⅡ 09-003 was uniformly coated on the plates containing 0.8% of lithium chloride.Cultured for 13 to 14 days in dark conditions at the temperature of 26℃～27℃ and relative humidity of 60%～65%,single colonies were picked,primary and secondary assays were made.Content was determined by HPLC method.The results showed that after UV irradiation for 180 s and the 0.8% dose of lithium chloride the lethality rate of strain was 88.6%.The mutant strains were screened and ultimately four high-producing strains were obtained such as TM Ⅱ 09-236,TM Ⅱ 09-253,TM Ⅱ 09-441 and TM Ⅱ 09-447.