Abstract：Objective The purpose of the study is to breed the mutanted Micromonospora echinoapora which can increase the antibiotic production of G-418. Methods By means of the mutagenesis of UV, NTG, microwave, and ultrasonic, combined with the bioactivity assay, the high-yield mutants were selected based on the titre of G-418. Results Two high-yielding strains were obtained with G-418 production increased by 102% and 115%, respectively, compared to the original strain. Conclusion This study shows that UV mutagenesis can significantly increase the positive mutation rate of G-418 producing strains, and especially the seed broth in the decline phase had the highest positive mutation rate, which lays a foundation for the breeding of G-418 high-yielding strains of Micromonospora.
