Abstract:Inorder to increase the daptomycin yield of Streptomyces roseosporus AN-126, the strain AN-126 was mutated by ARTP-DES compound mutagenesis combined with sodium decanoate tolerance. A mutant strain RR-447 with a yield of 101.41 mg/L was obtained, which was 2.44 times that of the strain AN-126. The genetic stability experiment showed that the high yield performance of the strain RR-447 was stably inherited. The morphological characteristics and gene fingerprints of strains AN-126 and RR-447 were analyzed. The strain RR-447 was not only different from strain AN-126 in morphological characteristics, but also had a specific band between 1.5 kb and 2.0 kb in its genome DNA. In 5 L fermentation tank, the daptomycin yield of strain RR-447 reached a maximum of 521.39 mg/L by adding sodium decanoate. The results show that ARTP-DES compound mutagenesis combined with sodium decanoate tolerance is an effective breeding method for breeding high-yield daptomycin strains, which provides a technical reference for industrial microbial breeding of daptomycin and other strains improvement.