响应面法优化冬虫夏草菌产多糖液体发酵培养基

Optimization of liquid fermentation medium for polysaccharide produced by Cordyceps sinensis using response surface methodology

本试验应用响应面法对冬虫夏草菌CC-10液体发酵培养基进行优化,以提高胞内多糖含量同时降低生产成本。试验以多糖含量为响应值,先通过单因素试验确定最适碳源和氮源,采用Plackett-Burman试验从7个培养基组分中筛选出主要影响因素,爬坡试验逼近最佳响应值区域,最终通过Box-Behnken Design和响应面分析确定主因素的最优浓度。结果表明:冬虫夏草菌CC-10产多糖的最适碳源为麦芽糖,最适氮源为蛋白胨,综合菌株生长特性和生产成本,选择葡萄糖、麦芽糖组合碳源和蛋白胨、豆饼粉组合氮源;确定葡萄糖、麦芽糖、蛋白胨3个主因素,得到最优的产多糖培养基为葡萄糖9.3 g/L、麦芽糖18.8 g/L、蛋白胨6.1 g/L、豆饼粉4 g/L、KH_2PO_41 g/L、MgSO_40.5 g/L、核黄素0.5 mg/L。优化后的多糖含量为4.23%,是优化前的2.06倍。试验为后续大规模发酵生产提供理论参考。

In order to enhance cell yield of polysaccharide and reduce production cost,this study used response sur-face methodology to optimize liquid fermentation medium of Cordyceps sinensis CC-10 strain.Taking the content of polysaccharide as response value,the single-factor design was used to screen the suitable carbon and nitrogen source. Plackett-Burman design was employed to screen main influence factors from seven medium components.Then the steepest ascent experiment was used to approach maximum response area.Last optimum levels of critical variables were determined by Box-Behnken Design.The results showed that maltose and peptone were screened as the optimal carbon source and ni-trogen source,respectively.Considering the growth characteristics of CC-10 strain and production cost,combination carbon source of glucose and maltose, combination nitrogen source of peptone and bean cake powder were chose.Glucose,maltose and nitrogen were identified as main influencing factors,the optimized composition were：glucose 9.3 g/L,maltose 18.8 g/L,peptone 6.1 g/L,bean cake powder 4 g/L,KH2PO4 1 g/L,MgSO4 0.5 g/L,riboflavin 0.5 mg/L.Under the optimum medi-um,cell yield of polysaccharide was up to 4.23%,which was increased by 1.06 times of previous optimization.The study could provide a theory reference for the mass production in the future.