Production and characterization of sterigmatocystin.

Fourteen strains of Aspergillus versicolor and 2 strains of A. nidulans were screened for sterigmatocystin (ST) production on a semi-synthetic solid substrate by high performance liquid chromatography (HPLC) analysis. Two strains of A. versicolor producing ST at 550.5 mg.kg-1 substrate and 1160.8 mg.kg-1 substrate were selected to inoculate 4 kg solid ST-producing media. After 30 days stationary incubation at 28 degrees C in the dark, 2271.6 mg of pale-yellow needle-shaped crystals were isolated and purified from the culture with a procedure applying column chromatography and recrystallization method. The crystal was proved to be sterigmatocystin by spectroanalysis and some physico-chemical analysis. The purity of the final material obtained were more than 99.9% as shown by HPLC and TLC detection. With this procedure, ST was obtained at about one tenth of its commercial cost.