中文摘要：

为提高Escherichia coli BL21（DE3）中漆酶基因lac1338的表达水平,采用响应面法对其发酵条件进行优化.首先用Plackett-Burman法筛选出3个影响较大的重要因素,分别为温度（Q1）、诱导时间（Q3）以及诱导前菌体浓度OD600 nm（Q4）.继而结合响应面分析,建立以漆酶酶活为响应值的二次回归方程模型,即Y=75.33＋3.30A＋9.35B＋5.35C-1.69AB＋0.80AC＋11.50BC-25.97A^2＋1.83B^2-4.66C^2,从中获得最优的发酵条件：诱导温度为31℃,诱导时间为20 h,诱导前的菌体浓度OD600 nm值为1.8.采用该发酵条件,供试菌株的漆酶比酶活达到22.8 U/mg,较优化前漆酶的表达量（10.7 U/mg）提高了2.13倍,其试验值与预测值基本相符.说明预测模型可靠性高,可应用于漆酶发酵条件的优化.

英文摘要：

In order to enhance the production of laccase in Escherichia coli BL21（DE3）, response surface methodology was applied to optimize the fermentation conditions. Plackett-Burman design was used to investigate the main factors affecting laccase yield of E. coli BL21（DE3）. The results showed that three factors played important roles in the fermentation conditions： the culture temperature（Q1）, culture time（Q3） and the initial bacteria density of OD600 nm（Q4）. The second-order regression equation model for the yield of laccase was established by response surface analysis as Y=75.33 ＋ 3.30 A ＋ 9.35 B ＋ 5.35C- 1.69 AB ＋ 0.80 AC ＋ 11.50BC- 25.97A^2 ＋ 1.83B^2- 4.66C^2. Based on this model, the optimal fermentation conditions were obtained as 20 h of culture time, 31 °C of culture temperature, and OD600 nm 1.8 of initial bacteria density. The ferment condition optimization increased the laccase production by nearly 2.13 times to 22.8 U/mg, with the experimental values in agreement with the predicted ones. These results suggested that the prediction model is reliable and suitable for the optimization of laccase fermentation conditions.