Optimization of the fermentation medium for maximization of meanquinone-7 (MK-7) production by Bacillus subtilis strain W J01 in static culture was carried out by using Response surface methodology (RSM).Maltose (carbon source),tryptone (nitrogen source),and glycerol (activator) were identified as the key medium components for MK-7 synthesis by fraction factorial design,and thus be selected for statistical optimization by RSM.The statistical analysis indicated that,in the range which was studied,maltose,tryptone,and glycerol were all critical factors having profound effects on the production of MK-7,with their coefficients for linear and quadratic all significant at p < 0.05 level.The established model was efficient and feasible,with the determination coefficient (R2) at 0.9419.According to these results,the predicated concentrations of maltose,tryptone,and glycerol in the optimal medium were determined as 36.78,62.76,and 58.90 g/L,respectively.In this optimized medium,the maximum yield of MK-7 reached a remarkably high level of 71.946±0.998 μg/mL after nine days statically fermentation with further verified the practicability of this optimum strategy.