蛹虫草固体发酵生产虫草素的条件优化

摘要

用直径6 cm,高10 cm聚乙烯培养罐固体发酵蛹虫草(Cordyceps militaris),以固体发酵产物中虫草素含量为指标,从16个蛹虫草菌株中筛选出虫草素含量最高的菌株,考察固体发酵该菌株的培养基组成、培养时间、培养基装量、料液比、培养温度、接种量和添加物对虫草素含量的影响,得到了有利于蛹虫草固体发酵产虫草素的培养条件:培养罐装20 g小麦,按小麦干重6％的量分别加入玉米粉和黄豆粉,按料液比1∶1.4(w∶v,以小麦干重为基准)加入营养液(g/L:2.0 K2HPO4·3H2O,0.5 MgSO4·7H2O,16甘氨酸),培养温度为26℃,时间46 d,接种量10％.%Cordyceps militaris strain 14 produced the highest amounts of cordycepin among 16 test strains when grown at 26 ℃ for 60 d in polyethylene culture bottles (diameter 6 cm,height 10 cm) containing 30 g wheat,1.8 g corn powder,1.8 g soybean powder and 30 mL nutrient solution (g/L∶2.0 K2HPO4 · 3H2O,0.5 MgSO4 · 7H2O).Selected parameters (cultivation time,substrate composition,weight of substrate in the cultivation bottle,solid-liquid ratio,cultivation temperature and inoculum size) affecting cordycepin production by this strain were then optimized using monofactorial analysis.Highest cordycepin levels in the cultivation substrate were recorded when polyethylene culture bottles containing 20 g wheat,1.8 g corn powder,1.8 g soybean powder,and 1.4 volumes of a nutrient solution consisting of (g/L) 2.0 K2HPO4 ·3H2O,0.5 MgSO4 · 7H2O and 16.0 glycine,were seeded with a 10％ inoculum of C.militaris strain 14 and incubated at 26 ℃ for 46 d.