Abstract: In order to screen strain producing high-yield avilamycin by mutagenesis, a wild-type strain Streptomyces viridochromogenes Tü57 was treated by a series of traditionally physical and chemical mutagenesis, resulting in the acquisition of numbers of forward mutants while judged by the great improvement in avilamycin A production. Genome shuffling was then carried out to fuse different sources of forward mutants, following with various fusants harvestry. The screening strategy adopted the combination method of thin layer chromatography (TLC) and cylinder-plate (two dosages technique) as the primary test, and high performance liquid chromatography (HPLC) as the secondary test. A mutant producing high-yield avilamycin, designated as R708, was obtained. The yield of avilamycin A from this mutant reached to 0.208 g/L in the shake flask experiment, which was a 20-fold increment compared to that of the wild-type strain. Our conclusion is that genome shuffling could increase the genetic diversity of the offspring strains; therefore this method is more quickly and efficiently than traditional mutagenesis in breeding strains producing high-yield avilamycin.

Key words: Streptomyces viridochromogenes Tü57, avilamycin, mutagenesis, genome shuffling