Abstract:

Response surface method was used to optimize the fermentation conditions of Bacillus mucilaginosus. Experiment factors and levels were firstly selected by one-factor tests. On the basic of the previous results and according to the Box-Behnken experimental design principles, the method of response surface method with 3 factors and 3 levels was adopted. Then the factors influencing were determined by means of regression analysis. After analysis on each significant and interaction effect, the results showed that the optimum fermentation conditions of Bacillus mucilaginosus as follows: yeast extract 0.53%, molasses 2.18%, pH 7.91. Then the largest number of bacteria predicted by the theoretical model was 1.853×108 cfu. After fermentation conditions optimization, the error of test value and predictive value was 0.7%. The experimental data and the predicted value of model fit well.