为了提高β-环糊精葡萄糖基转移酶产酶活力,应用Plackett- Burman设计法对影响高温菌株HY15发酵的10个因素进行了筛选,确定了主要影响因素,然后通过响应面法优化了各因素的最优质量浓度,建立了β-环糊精葡萄糖基转移酶产率的二次多项式数学模型,并分析了模型的有效性与因子间的交互作用.结果表明:影响β-环糊精葡萄糖基转移酶产率的主要因素及其最优质量浓度为:糖蜜+玉米淀粉22.45 g/L,K2HPO40.97 g/L,MgSO40.18g/L,玉米浆+酵母21.82 g/L,pH值6.98.在优化后的培养基条件下,β-环糊精葡萄糖基转移酶酶活力达到1 409.70 U/mL,验证值1401.81 U/mL,二者吻合较好.%The objective of this study was to obtain the optimum fermentation conditions for β-cyclodextrin glycosyltransferase (β-CGTase) by thermophilic strain HY15 in order to improve β-CGTase activity. The Plackett-Burman design was used to e-valuate the effects of ten influence factors on β-CGTase yield. Response surface methodology was applied to determine the maximum β-CGTase yield at the optimum concentration of the main influence factors. A quadratic polynomial model for β-CGTase yield was established. The optimal fermentation conditions for β-CGTase yield were determined. The model was validated, and the interactions between the influence factors were also analyzed. The main factors influencing β-CGTase yield and the optimal values of the five factors were determined as molasses plus corn starch 22. 45 g/L, K2HPO4 0. 97 g/ L, MgSO4 0.18 g/L, corn steep liquor plus yeast extract 21. 82 g/L, and pH 6. 98. The theoretical activity of β-CGTase was 1 409.70 U/mL, which agrees well with the experimental value (1 401.81 U/mL) under the optimum conditions.
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