Mutation breeding of high- yield strain of bacitracin

The purpose of this article was to select effective method to breed high- yield strains of bacitracin.Using bacillus licheniformis FUN- BL as an aboriginal strains, the positive mutants were screened by cup- plate method and HPLC after ultraviolet and diethyl sulfate. The aboriginal strains F0 mutated through ultraviolet ( 15 W, the irradiation distance of 30 cm and the irradiation time of 120 sec) were screened in repeat to obtain the high- yield strain of bacitracin F167, whose titer was improved by 11.76%.Then F167 mutated through diethyl sulfate ( dealt with2% diethyl sulfate for 90min) were screened in repeat to obtain the high- yield strain of bacitracin F2141, whose titer was improved by 32.19%. Making the high- yield strains F2141 do the genetic stability test for five successive generations, the titer followed 1003.23, 989.34, 976.35, 960.32, 949.72 U / m L. High- yield strains of bacitracin can be bred by ultraviolet and diethyl sulfate.