响应面法优化木糖醇发酵培养基

Statistical Optimization of Fermentation Medium for Xylitol Production by Response Surface Methodology

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.