运用多元数学模型优化灰树花发酵培养基组成的研究

利用BoxBehnken3×3设计优化了影响灰树花深层发酵菌丝体和胞外多糖生产的主要培养基组成,碳源(葡萄糖)、氮源(蛋白胨)和无机盐(KH2PO4),响应面分析结果表明,各因素及其交互作用对响应值灰树花菌丝体和胞外多糖产量均存在显著的相关性。通过典型性分析,获得最大菌丝体量(17.61g/L)时,培养基组成为:葡萄糖45.2g/L,KH2PO42.97g/L,蛋白胨6.58g/L,MgSO4·7H2O1g/L和玉米浆15g/L;而获得最佳胞外多糖量(1.326g/L)时的培养基组成为:葡萄糖58.6g/L,KH2PO44.06g/L,蛋白胨3.79g/L,MgSO4·7H2O1g/L和玉米浆15g/L。与其他实验组的结果相比,优化后的灰树花菌丝体与胞外多糖的量都有较大的增加。15L发酵罐扩大培养的结果表明,在优化培养基组成的条件下,扩大培养后的菌丝体产量最大值达22.50g/L。

Optimization of the Medium Composition for Production of Mycelial Biomass and exo-polymer by Grifola frondosa GF9801 Using Response Surface Methodology

In this work, a three-level Box-Behnken factorial design was employed combining with response surface methodology (RSM) to optimize the medium composition for the production of the mycelial biomass and exo-polymer in submerged cultures by Grifola frondosa GF9801. A mathematical model was developed to show the effect of each medium composition and their interactions on the production of mycelial biomass and exo-polymer. The model estimated that a maximal yield of mycelial biomass (17.61 g/L) could be obtained when the concentrations of glucose, KH_2PO_4, peptone were set at 45.2 g/L, 2.97 g/L, 6.58 g/L, respectively; while a maximal exo-polymer yield (1.326 g/L) could be achieved when setting concentrations of glucose, KH_2PO_4, peptone at 58.6 g/L, 4.06 g/L and 3.79 g/L, respectively. These predicted values were also verified by validation experiments. Compared with the values obtained by other runs in the experimental design, the optimized medium resulted in a significant increase in the yields of mycelial biomass and exo-polymer. Maximum mycelial biomass yield of 22.50 g/L was achieved in a 15-L fermenter using the optimized medium.