Abstract：The antagonistic strain (Bacillus subtilis) DS45-2 were cultured in NB medium for 48h at 30℃. The supernatant was collected by centrifugation at 8000r/min for 15 min at 4℃. The crude extracts of antifungal protein was obtained from the cell free supernatant of fermentation liqour of DS45-2 strain by ammonium sulphate precipitation. Assays for the antifungal activity of crude extracts were done on agar plates. The antifungal protein was found to be thermostable, resistant to pepsinum and trypsin, and partially sensitive to proteinase K. Its active pH range was wide, from 4.0 to 10.0. A antifungal protein purified by DEAE Sepharose Fast Flow chromatography and reversion phase chromatography, It’s molecular weight was estimated to be 23 k daltons by SDS-PAGE. It is significant to clone the genes because the antifungal proteins were greatly inhibitory to Verticillium dahliae Kleb.
