响应面法结合满意度函数优化白囊耙齿菌发酵培养基

Improvement of Medium for the Fermentation of Irpex lacteus Fr.by Respond Surface Methodology Coupled with Desirability Function

采用响应面法和满意度函数,以期望值作为响应值,提高白囊耙齿菌发酵的菌丝体干重以及胞内多糖、甘露醇、腺苷和蛋白质的含量。通过单因素法优化白囊耙齿菌发酵培养基中的碳、氮源和无机盐,然后进行部分因子试验考察培养基组分对菌株发酵的影响,并应用中心组合设计试验优化培养基,获得最佳培养基配方(%):乳糖2.94,酵母浸粉1.5,牛肉膏1.5,KH_2PO_4·3H_2O 0.065,MgSO_4·7H_2O 0.06,NaCl 0.000 8,VB_1 0.028 9。模型预测最佳培养基配方下白囊耙齿菌的发酵期望值为0.624,3次验证试验平均值为0.617 7,是优化前的5.27倍,与模型预测值间的误差为1.01%。

A respond surface methodology coupled with desirability function was used to optimize the Irpex lacteus Fr fermentation medium for simultaneous enhancing the yields of mycelium, intracellular polysaccharide, mannitol, adenosine and protein. Suitable carbon sources, nitrogen sources and inorganic salts were chosen by single- factor tests. On the basis of single-factor tests, fractional factorial design was used for identifying the significant components and Box-Behnken design was used for further optimization. The obtained optimal medium ingredients （%） were： lactose 2.941, yeast extraction powder 1.5, beef extract 1.5, KH2PO4·3H20 0.065, MgSO4·7H20 0.06, NaCl 0.000 8 and VB1 0.028 9. The expected desirability value （D） of the optimum fermentation medium was 0.624. Three validation experiments were implemented with the optimum fermentation medium and their average D was 0.617 7, which was 5.27 times of that obtained under the pre-optimized medium. The relative error between the experimental values and the expected value was 1.01%, which indicated that the expected values fit experimental values.