Protoplast formation,regeneration and UV mutagenesis of natamycin producing Streptomyces gilvosporeus

The conditions of protoplast formation,regeneration and UV mutagenesis of Streptomyces gilvosporeus were studied.It was beneficial under the conditions of late exponential phase cell(48 h) with 0.4% lysozyme at 30℃ for 90min. After regeneration,about 73.3% strains' production of natamycin was increased,and the production of natamycin by mutant 5-12 reached 2121.2μg/mL,which was 74.7% more than that of the parent strain.After UV mutagenesis,five high producing strains were obtained,and the production by UV-2 was 107.09% more than that of the parent strain.Its production reached 2515.07μg/mL.