Conagenin, a low molecular weight immunomodulator produced by Streptomyces roseosporus.

effect on T lymphocytes. Fermentations for the production of conagenin were done as follows. S. roseosporus was cultured in 500-ml Erlenmeyer flasks containing 1 10 ml of the autoclaved seed medium consisting of galactose 2.0%, dextrin 2.0%, soy peptone 1.0%, corn steep liquor 0.5%, (NH4)2SO4 0.2%, CaCO3 0.2% and one drop of silicone. The seed medium was adjusted to pH 7.4 with 1 n HC1 and was autoclaved for 20 minutes. Fermentations were carried out on a rotary shaker (180rpm) at 27°C for 48 hours. Three ml of the mature seed fermentation were inoculated into 500-ml flasks containing 110ml of the autoclaved production medium consisting of maltose 2.0%, meat extract 0.5%, peptone 0.5%, yeast extract 0.3%, NaCl 0.3%, and MgSO4-7H2O 0.1%, supplemented with 0.1 ml of a mixture of inorganic salts consisting of CuSO4-5H2O 0.6%, FeSO4-