Oxytetracycline production by Streptomyces rimosus in solid-state fermentation of corncob.

Corn-cob was used as a substrate in the production of oxytetracycline by Streptomyces rimosus TM-55 in a solidstate fermentation. Oxytetracycline was detected on day 4, and reached its maximum on day 8. Optimal conditions for oxytetracycline production were an initial pH of 5.2 to 6.3, an initial moisture content of 64% to 67%, supplementation with 20% (w/w) rice bran or 1.5% to 2.5% (w/w) (NH4)2SO4 as sole N source, 1.0% (w/w) CaCO3, 2% (w/w) MgSO4.7H2O, and 0.5% (w/w) KH2PO4, with incubation for 8 days at 25 to 30°C. Each g substrate produced 7 to 8 mg oxytetracycline.