利用响应面法优化非致病性尖孢镰刀菌FJAT-9290固体发酵培养基

为优化生防菌非致病性尖孢镰刀菌菌株FJAT-9290的固体发酵培养基配方,以农业副产物——微生物发酵床养猪垫料和麸皮作为基础培养基,采用单因素试验考察麦粒、蔗糖和硝酸钠对菌株产孢量的影响,通过Box-Benhnken试验设计和响应面分析法,建立以产孢量为响应值的多元二次回归模型,确定菌株固体发酵的最优培养基配方。结果表明,建立的模型差异极显著(P0.0001),可以用该模型来拟合试验。菌株FJAT-9290在垫料和麸皮质量比17:3的基础培养基上,其他成分的最佳添加量分别为麦粒39.14%、蔗糖2.97%和硝酸钠0.30%,采用该优化组合的菌株平均产孢量可达2.48×10~8孢子/g。响应面结果也表明,各因素对产孢量的影响结果排序为麦粒蔗糖硝酸钠,其中蔗糖和硝酸钠两因素的交互作用最显著。

Optimization of Solid-state Fermentation Culture for Biocontrol Agent Non-pathogenic Fusarium oxysporum FJAT-9290 by Response Surface Methodology

The medium components were optimized for solid-state fermentation of a biocontrol agent,non-pathogenic Fusarium oxysporum FJAT-9290.The agricultural by-products,such as bran or pig raising litter from microbial fermentation beds (MFB),were used as basic culture media.A single factor experiment was carried out to investigate the effects of kernel,sucrose and sodium nitrate on the conidia of the strain.Then,the process parameters were optimized by using Box-Behnken experimental design and the results were analyzed with response surface methodology (RSM).A multiple quadratic regression model with conidia as response value was established to determine the optimal medium component.The results showed that the regression model performed highly significant difference (P＜0.0001) and could be used to fit the experiment.When MFB and bran with a weight ratio of 17∶3 were used as basic culture media,the optimal additive amounts of kernel,sucrose and sodium nitrate were confirmed to be 39.14％,2.97％ and 0.30％,respectively.The average conidia of the strain could reach to 2.48 × 108 conidia/g under condition of the optimal medium component.The RSM analysis also indicated that the influence on conidia were kernel＞ sucrose ＞ sodium nitrate,and the interaction between sucrose and sodium nitrate was the most significant.