Effect of culture media on protease and oxytetracycline production with mycelium and protoplasts of Streptomyces rimosus

For the simultaneous production of protease and oxytetracycline, mycelium and protoplasts of Streptomyces rimosus TM-55 were cultivated in basal medium containing soluble starch, corn steep liquid, ammonium sulphate, calcium carbonate, sodium chloride and soybean oil. Protease and oxytetracycline production increased with decreasing in ratio of culture broth to vessel volume from 1:2 to 1:5. Each ml of broth with 0.286 mg fresh mycelia yielded 168-204 units of protease and 785-972 mug of oxytetracycline after replacement of corn steep liquor, sodium chloride and soybean oil with beef extract and sunflower oil, while each ml of broth with 7.5 x 10(7) protoplasts produced 141-153 units of protease and 504-615 mug of oxytetracycline. Protease and oxytetracycline production were low when the pH was less than or equal to5.1 or greater than or equal to9.0. Soluble starch and ammonium sulphate were the best carbon and nitrogen sources, respectively. Supplementation with calcium carbonate enhanced protease and oxytetracycline production. The productivity of protoplasts decreased sharply when the incubation temperature increased from 28 to 34 degreesC, while the productivity of mycelium was almost unchanged.