本实验室从天然土样中筛选出一株以木糖为能够耐受高浓度木糖产木糖醇的酵母Y-9。为了提高转化木糖醇的产量,利用Placket-Burman设计和响应面法对产木糖醇菌株发酵培养基进行优化,首先通过Placket-Burman设计筛选出影响较大的三个因素,分别为酵母膏、硫酸铵、硫酸锌,然后进行最陡爬坡实验逼近最佳响应面区域,最后根据Box-Benhnken的中心组合设计原理,进一步进行响应面分析实验,得到3因素的最佳浓度。在优化培养基下,木糖醇产量达163 g/L,比优化前提高了42%。

A yeast strain Candida sp .Y-9 was isolated from soil samples in our laboratory , which could tolerate high concentrations of xylose .In order to improve xylitol production by Candida sp .Y-9,Placket-Burman ( PB) and response surface methodology ( RSM) were used to optimize the fermentaiton medium . First ,three factors ,ammonium sulfate ,yeast extract and zinc sulfate were screened by the Placket-Burman design .Then, the optimal response surface area was approached by the steepest ascent experiment . Finally, response surface analysis was performed based on the principles of Box -Benhnken central composite design to obtain the optimum concentrations of the three factors .As a result ,xylitol yield could reach up to 163 g/L under the optimized medium , which was 42% higher than the initial fermentation levels.

微生物的发酵过程十分复杂,培养基配方的组成以及培养条件的变化都会对菌体的代谢造成很大的影响。为了使抗生素的产量达到最大化,试验运用了Plackett-Burman试验设计、最陡爬坡试验、BoxBehnken试验设计对放线菌(Actinomycetes)G5进行了发酵条件优化。利用Plackett-Burman试验设计对影响放线菌G5发酵的诸多相关因素进行评估并筛选出3个主要因素,即碳源含量、培养温度和培养时间;之后根据3个主要因素的作用大小和方向进行了最陡爬坡试验;最后运用Box-Behnken试验设计确定最优值,得出其最优培养条件为淀粉含量21.66 g/L、培养温度27.70℃、培养时间7.75 d。在此条件下,抗生素对苹果轮纹病菌的抑菌圈直径为23.00 mm,与模型预测值基本一致。

Microbial fermentation process were very complex due to effects of culture medium composition and culture condi-tions on cell metabolism. Fermentation conditions for actinomycetes G5 were optimized with Plackett-Burman experimental de-sign, steepest ascent experiments, and Box-Behnken design. Three main factors affecting the fermentation of actinomycetes G5 screened by Plackeet-Burman design were carbon content, temperature and culture days. Then the steepest ascent experiments were conducted based on the action degree and direction of the three main factors. The optimal conditions were finally deter-mined by Box-Behnken design. The results showed that the optimal fermentation condition for actinomycetes G5 were starch content of 21.66 g/L, culture temperature of 27.70℃ and culture days of 7.75 d. Under these conditions, the bacterial inhibi-tion diameter of the acquired antibiotics against physalospora piricola was 23.00 mm, equal to the model prediction.

通过单因素试验筛选出大豆花粉萌发培养基最佳碳源为蔗糖，Ca2＋源为CaCl2，有效植物生长调节剂为GA3；采用Plackett-Burman设计法对选取的8个相关影响因素进行了评价，筛选出3个主要影响因素，分别为初始pH、蔗糖和GA3，且3个因素在PB设计的水平范围内对响应值的影响均为正效应。

In the germination experiment of soybean pollen, single factor design was used and found that the best carbon source was sucrose, suitable Ca2+source was CaCl2, and the productive plant hormone was GA3. Subsequently, the methodology of Plackett-Burman design was undertaken to evaluate the influence of the eight related factors. Three parameters significantly influenced germination, they were the initial pH, sucrose and GA3, and all of them influenced the germination of soybean pollen positively within designed level.

利用超声波辅助提取紫甘薯中的紫甘薯色素,在单因素实验的基础上,采用Plackett-Burman试验设计对超声波提取的因素进行了研究,筛选出对超声波提取紫甘薯色素具有显著影响的因子为超声波功率(P0.000 1),提取次数(P=0.000 9)和料液比(P=0.002 8),并得到了以紫甘薯色素提取率为响应值的线性回归方程,为进一步的响应面优化提供了参考。

Ultrasonic wave was used to extract the pigment from purple sweet potato. On the base of single experiments, Plackett-Burman design was applied to study the factors of ultrasonic extraction and screen out the key factors:ultrasonic power(P<0.000 1), extraction of times(P=0.000 9)and ratio of solid to solution(P=0.002 8). The linear regression equation of pigment''s yield as response value was obtained , and the results can provide a reference for the further optimization by using Response Surface Method.

旨在优化地衣芽孢杆菌(Bacillus licheniformis)AM53的发酵条件。通过Plackett-Burman试验筛选到影响AM53活菌数的重要因素为培养温度、初始pH、摇床转速。经最陡爬坡试验和Box-Behnken试验,获得AM53的最佳发酵条件为培养温度30.5℃,初始pH8,摇床转速185 r/min,接种量为5%,培养24 h。结果显示,在此条件下,OD600平均为1.861,其值与预测值基本相符,说明该模型可信度高,可应用于AM53发酵条件优化。

It was to optimize the fermentation conditions of Bacillus licheniformis. The Plackett-Burman design was used to optimize the fermentation conditions, and the results showed that culture temperature, the initial pH and the rotating speed had significant influence on the count of the living AM53. After the steepest ascent test and Box-Behnken design, the optimal fermentation conditions of AM53 that we got were:culture temperature was 30.5℃, the initial pH was 8, rotating speed was 185 r/min and inoculation volume was 2%, cultured 24 hours. Under this condition, the average of OD600 was 1.861, which means the experimental values agreed with the predicted values, the predicted model was reliable and available for the optimization of AM53 fermentation conditions.