Optimization of fermentation conditions for Bacillus subtilis M6 on the biological control of protected vegetable

The article studied the fermentation technology and optimized the fermentation medium for the Bacillus subtilis M6 on the protected vegetable by single factor experiments and orthogonal experiments.The results showed that the optimum condition of the Bacillus subtilis M6 were cornstarch 10g/L,soy protein powder 8g/L,NaCl 5g/L,K2HPO4 0.6g/L,initial pH value of the medium 7.0,temperature 35℃.inoculation volume 8%,rotation speed 180r/min,fermentation time 42h.Under the optimized conditions,the microbe number of the bacillus subtilis M6 could reach 95.8×l08cfu/ml in the fermentation liquid and the spore ratio was over 92%.The microbe number of the Bacillus subtilis M6 was increased by 12.7% compared to that(85×l08cfu/ml) before the optimization.