响应面法优化异硫链霉菌LMZM利用玉米芯粉产木聚糖酶发酵培养基的研究

Study on optimization of culture medium for xylanase production by Streptomyces althioticus LMZM using response surface methodology with corncob

本研究采用响应面法对异硫链霉菌LMZM产木聚糖酶的发酵培养基进行优化。首先利用Plackett-Burman实验设计筛选出影响产酶的4个显著性因素:玉米芯粉、大豆粉、酵母粉和MgSO——4。在此基础上,研究不显著因素的最低添加量来降低生产成本,然后运用最陡爬坡法逼近最大响应值区域,最后利用中心复合设计确定显著性因素之间的交互作用及最佳组成。结果表明,玉米芯粉27.85 g/L、大豆粉16.25 g/L、酵母粉3.46 g/L、MgSO_41.18 g/L、K_2HPO_40.60 g/L、Na_2HPO_40.40 g/L,木聚糖酶最大理论酶活可达117.80 U/m L,经3次平行实验验证,实际酶活平均值为116.63 U/m L与预测酶活相近,且比优化之前的酶活提高了1.28倍。

In this study,response surface methodology（ RSM）was employed to optimize a fermentation medium for the production of Streptomyces althioticus LMZM in submerged fermentation with corncob as substrate. Four significant influence factors including corncob powder, soybean ,yeast extract powder and magnesium sulfate were screened by the method of Plackett-Burman design. In addition, the minimum addition amount experiment was used for finding out the minimum add amount of non-significant factors to reduce the source cost.The steepest ascent design was applied to approach the optimal region of the three significant factors. And the optimal concentration and correlations among three factors were identified by central composite design. The optimal fermentation parameters for enhanced xylanase production were found to be corncob powder 27.85 g/L,soybean 16.25 g/L,yeast extract powder 3.46 g/L,magnesium sulfate 1.18 g/L, potassium phosphate dibasic 0.60 g/L and disodium hydrogen phosphate 0.40 g/L.The model predicted a xylanase activity of 117.80 U/mL.After three parallel verifications,the maximum theoretic value was consistent with mean value of verification test which was 116.63 U/mL, and the xylanase production was increased by 1.28-fold in comparison with to that before optimization