Nitrosoguanidine Mutagenesis and Genome Shuffling Enhanced the Oxytetracycline Production of Streptomyces rimosus

This research is aimed to improve the oxytetracycline production from Streptomyces rimosus. Five relatively high oxytetracycline yielding strains were obtained by nitrosoguanidine mutation of the protoplast of initial oxytetracycline producing strain Streptomyces rimosus JH and then subjected to genome shuffling as parental strains. The protoplasts of the five parental strains were prepared and inactivated before fusion, after recursive protoplast fusion of six rounds, the oxytetracycline production of all recombinants in shaking-flask fermentation was analyzed by ultraviolet spectrophotometer method comparing with the initial strain IH. The result indicated the yield of oxytetracycline was enhanced. The highest production of recombinant 26173 was about 186% higher than that of the highest-production parent strain and 339.8% higher of the initial strain. In result, genome shuffling is a good technique to rapidly improve oxytetracycline production in Streptomyces rimosus.