摘要:To improve antagonistic metabolites production of Bacillus subtilis strain BS501a,physical parameters of fermentation and metal inorganic salts in medium,namely initial pH value,culture temperature,fermentation time,concentrations of CaCl2,FeSO4,ZnSO4,MnSO4 and MgSO4,were optimized using one-factor-at-a-time and orthogonal tests.The results show that the optimal physical parameters of fermentation are an initial pH of 7.0,a culture temperature of 30 °C,and a fermentation time of 48 h.The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl2,0.4 mmol/L FeSO4,3.5 mmol/L ZnSO4,0.6 mmol/L MnSO4 and 2.0 mmol/L MgSO4.Among the metal inorganic salts,MgSO4 and MnSO4 play important roles in the improvement of the antagonistic metabolites production of B.subtilis strain BS501a;especially,MgSO4 contributes a highly significant effect.The average diameter of inhibition zone of the BS501a filtered fermentation supernatant(FFS) cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm,and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions.