The cultural conditions and antifungal substances of Bacillus subtilis SNUB16 were investigated by determinating the inibition of cell-free fermentation filtrate to Fusarium oxysporum.The results showed that PDA medium is favorable to cell growth and production of antifungal substance. After 60~72 hours culture at 30 ℃, initial pH of 7.2, oscillation rate of 170rpm, the cell-free fermentation filtrate has the highest antifungal activity to Fusarium oxysporum.The antifungal activity is not affected by heat at 50 ℃ for 30 min, but it decreases as the filtrate is heated at 60 ℃ for 30 min. Antifungal activity loses 50% when the filtrate is heated at 100 ℃ for 30 min, and antifudgal activity completely loses when the filtrate is heated at 121 ℃ for 30 min. The antifungal activity cannot be affected at the pH of 6~7, but excess acid or alkaline can make its antifungal activity lose gradually,and the effect of excess alkaline is stronger than that of excess acid.The filtrate loses part of its antifungal activity when the filtrate is treated in presence of protease K,indicating that the primary antifungal substances produced by Bacillus subtilis SNUB16 are protein and non-protein.

Bacillus subtilis SNUB16； cultural condition； character of antifungal substances