液体发酵条件对广东虫草菌丝生物量和胞外多糖产量的影响

摘要

The effects of temperature,initial pH,carbon and nitrogen sources,and C∶N ratio on mycelial biomass and exopolysaccharide (EPS) production by Cordyceps guangdongensis grown in submerged culture were evaluated.Mycelial growth was optimal at 25 ℃,an initial pH range from 7.0 to 9.0,and with malt extract and soybean steep powder as the carbon and nitrogen sources,respectively.EPS production was maximal at 28 ℃,an initial pH range from 5.0 to 7.0,and with glucose and yeast extract as the carbon and nitrogen sources,respectively.Both biomass and EPS production were favored by a C∶N ratio of 12 ∶ 1.Orthogonal testing revealed the optimal medium for mycelial biomass production to consist of 30 g/L glucose,30 g/L malt extract,8 g/L soybean steep powder and 10 g/L yeast extract,and for EPS production to consist of 40 g/L glucose,30 g/L malt extract,10 g/L soybean steep powder and 10 g/L yeast extract.%研究了液体发酵的温度、起始pH、碳源、氮源和碳氮比对广东虫草菌丝生物量和胞外多糖的影响.当发酵温度为25℃,培养基起始pH为7.0～9.0,麦芽膏和大豆浆粉分别为碳氮源时菌丝生物量最高；当发酵温度为28℃,培养基起始pH为5.0～7.0,葡萄糖和酵母膏为碳氮源时胞外多糖产量最高；以菌丝生物量和胞外多糖的产量为指标最优的碳氮比为12∶1.正交试验表明:以菌丝生物量为指标,优化的培养基为30 g/L葡萄糖,30 g/L麦芽膏,8 g/L大豆浆粉和10 g/L酵母膏；以胞外多糖产量为指标,优化的培养基为40 g/L葡萄糖,30 g/L麦芽膏,10 g/L大豆浆粉和10 g/L酵母膏.