不同浓度碳源和氮源对灰树花胞外多糖液体发酵产量的影响

以灰树花(Grifola frondosa)BUAGF-02 菌株为材料，研究葡萄糖和蛋白胨浓度对液体发酵产多糖的影响。研究以可溶性淀粉、葡萄糖、酵母提取物、蛋白胨等基础发酵培养基，碳源试验葡萄糖浓度分别为5、10、15、20、25 g/L，氮源试验蛋白胨浓度为1、1.5、2、2.5、3 g/L，25℃、170 r/min 振荡培养10 天，离心收集发酵液和菌丝体，采用醇沉法收集多糖，菌丝体和多糖烘干后称重。葡萄糖浓度在20 g/L 时，胞外多糖产量最高，达到0.3 g/100 mL；其浓度25 g/L时菌丝体干重最高，为1.82 g/100 mL。蛋白胨浓度3 g/L时，胞外多糖产量最高，为0.2 g/100 mL；其浓度2.5 g/L 菌丝体干重最高，为1.26 g/100 mL。研究为进一步开展灰树花胞外多糖液体发酵与利用提供了参考。

Effects of Different Concentrations of Carbon and Nitrogen Sources on Production of Grifola frondosa Extracellular Polysaccharides

In the present study, Grifola frondosa strain BUAGF-02 was used for evaluation of glucose and peptone concentrations on extracellular polysaccharides production. Soluble starch, glucose, yeast extract, peptone, etc were used as basic fermentation medium. 5, 10, 15, 20 and 25 g/L of glucose and 1, 1.5, 2, 2.5 and 3 g/L of peptone were used in glucose and peptone assay respectively. The media were shaken and cultured at 25℃ and 170 r/min for 10 d followed by a centrifugation. Mycelia and supernatant were collected. Polysaccharides were collected using the ethanol precipitation method. Both mycelia and polysaccharides were dried and weighted. The results showed that yield of polysaccharides reached the highest level of 0.3 g/100 mL at glucose concentration of 20 g/L, while the highest mycelial weight of 1.82 g/100 mL was achieved at glucose concentration of 25 g/L. The yield of polysaccharides reached the highest level of 0.2 g/100 mL at peptone concentration of 3 g/L, while the highest mycelial weight of 1.26 g/100 mL was obtained at peptone concentration of 2.5 g/L. The study is of certain values to further fermentation researches and applications of G. frondosa polysaccharides.