忍冬桑黄和蛹虫草共发酵联产真菌多糖初步研究

忍冬桑黄和蛹虫草两种药用真菌均可产活性多糖,共发酵模式是产生新化合物或提高化合物含量或药效的潜在方式。本研究尝试用忍冬桑黄和蛹虫草共发酵联产真菌多糖,并对其共发酵所得的菌丝体多糖开展抗氧化活性试验。结果表明,当忍冬桑黄和蛹虫草预先分别发酵3d和1d后再同时接种共发酵,两菌可以较好地进行共生长,菌体总量和总多糖得率显著高于两菌单独进行发酵时的相应量。进一步对适宜两菌共发酵的培养基进行了优化,获得适宜两菌共发酵高产多糖的培养基组成为：可溶性淀粉30g/L、牛肉粉12g/L、磷酸氢二钾和硫酸镁各1.5g/L。共发酵菌丝体中多糖和黄酮含量均高于两菌单个菌体中的相应含量,但三萜含量和桑黄菌体中的三萜含量没有显著差异。抗氧化活性试验表明,共发酵菌体多糖、忍冬桑黄菌体多糖和蛹虫草菌体多糖对DPPH·自由基、羟基自由基、超氧阴离子自由基均具有清除作用,其中共发酵菌体多糖对3种自由基的清除作用显著强于两菌单个菌体多糖的清除效果。本研究表明忍冬桑黄和蛹虫草共发酵联产真菌多糖具有可行性。

A preliminary study on co-fermentation of Sanghuangporus lonicericola and Cordyceps militaris to produce fungal polysaccharides

Both Sanghuangporus lonicericola and Cordyceps militaris can produce active polysaccharides. Co-fermentation mode is a potential way to produce new compounds or improve the content or bioactive efficacy of compounds. In this study, the co-fermentation of S. lonicericola and C. militaris was performed to produce polysaccharides, and the antioxidant activities of the mycelial polysaccharides were tested. The two fungal strains separately prefermented for 3 days and 1 day, and then in the same flask continuously fermentated. It was found that the total amount of biomass and the yield of total polysaccharides were significantly higher than those of the two strains when they were fermented individually. The suitable medium for co-fermentation was optimized, and the optimized medium was as follows: soluble starch 30g/L, beef powder 12g/L, potassium hydrogen phosphate 1.5g/L, and magnesium sulfate 1.5g/L. The content of polysaccharides and flavonoids in co-fermentation mycelium were higher than those in mycelium of the two strains fermentated individually, but there was no significant difference in triterpenoid content between co-fermentation mycelium and S. lonicericola mycelium of separated fermentation. Antioxidant activity test showed that either the co-fermented polysaccharides, or separately fermented S. lonicericola polysaccharides and C. militaris polysaccharides had scavenging effect on DPPH· free radical, hydroxyl free radical and superoxide anion free radical, but the scavenging effect of co-fermented polysaccharides was significantly stronger than that of the polysaccharides obtained from the two strains individually fermented. The results suggest that the co-fermentation of S. lonicericola and C. militaris was feasible.