摘要
在Plackett Burman实验设计结果基础上 ,采用响应曲面法 (ResponseSurfaceMethodolo gy,RSM)对影响翅鳞伞 (Pholiotasquarrosa)AS 5 2 4 5发酵胞外多糖与菌丝生长的关键影响因子最佳水平范围进行了研究和探讨。通过对胞外多糖曲面方程以及菌丝干重二次多项回归方程求解得知 ,在自变量培养温度 ,培养时间和装液量分别为 2 8 0 7℃、 8 79d和 68 5 1mL时 ,翅鳞伞胞外多糖的最大预测值为 1 0 62 69μg·mL 1发酵醪 ;2 7 60℃、 9 42d和 5 4 2 0mL时 ,该菌菌丝浓度可达 1 1 32mg·mL 1发酵醪 ;而在 2 7 62℃、 9 1 9d和 64 1 0mL的工艺条件下 ,每毫升发酵醪则可同时获得 1 ,0 5 0 64μg的胞外多糖和 1 1 1 0mg的干菌丝。上述预测值不仅被统计学方法所验证 。
Response surface methodology (RSM) based on a three-level three-factor Box-Behnken design of experiments was used to optimize the extracellular polysaccharide content and the mycelium biomass by submerged cultivation using Pholiota squarrosa AS 5.245. The critical factors selected for the investigation were temperature, time of cultivation and volume of medium, based on the results of our previous Plackett-Burman design. The objectives of this present work were to locate optimum levels of these process parameters, and to find out interactions among them for enhancement of the yield of extracellular polysaccharide and mycelium biomass. By solving the regression equation and also by analyzing the response surface contour plots, the optimal process conditions were determined: under conditions of temperature, 28.07℃; cultivation time, 8.79 d and volume of medium, 68.51 mL, the prediction of extracellular polysaccharide content (EPC) by Pholiota squarrosa AS 5.245 was 1062.69 μg per milliliter of fermentation liquor. While cultivation temperature, time and volume of medium were 27.60℃, 9.42 d and 54.20 mL respectively, the mycelium biomass expressed as dry cell weight (DCW) was 11.32 mg·mL -1. In order to simultaneously obtain the maximum yield of EPC and DCW, the above conditions would be located at 27.62℃, 9.19 d and 64.10 mL. In these conditions, the maximum predicted yield of EPC and DCW were found to be 1050.64 μg·mL -1 and 11.10 mg·mL -1, respectively. These predicted values were also verified by validation experiment.
出处
《微生物学通报》
CAS
CSCD
北大核心
2004年第6期42-47,共6页
Microbiology China
