title: Enhanced sinefungin production by medium improvement, mutagenesis and protoplast regeneration of Streptomyces incarnatus NRRL 8089.
abstract: Increased production of sinefungin, a very potent antifungal and antiparasitic nucleoside antibiotic was achieved by medium and strain improvement. When soybean-meal, dextrin and yeast extract were added as carbon and nitrogen sources to the fermentation medium, instead of corn steep liquor, soya-oil and glucose; the antibiotic yield increased from 40 micrograms/ml to 126 micrograms/ml with low biomass production. Strain improvement was attempted by two methods. The mean antibiotic yield of the variants after multistep mutagenesis by N-methyl-N'-nitro-N-nitrosoguanidine and ethyleneimine was 466 micrograms/ml. Protoplasts of the parental strain were prepared by lysozyme digestion from mycelia grown in a medium containing 0.7% glycine. The mean activity of the regenerated protoplasts was 664 micrograms/ml. Thus, the overall sinefungin production could be increased 16-fold.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D000935:Antifungal Agents / Q000096:biosynthesis*; D000962:Antimalarials / Q000378:metabolism*; D003470:Culture Media; D005285:Fermentation; D009154:Mutation; D011523:Protoplasts / Q000502:physiology; D012038:Regeneration; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D000962:Antimalarials; D003470:Culture Media; D000241:Adenosine; C006235:sinefungin