通过诱变获得高产胞外虫草素和虫草多糖的蛹虫草菌株.采用紫外线诱变(UV)、化学诱变(LiCl)、复合诱变(UV-LiCl) 3种方式对蛹虫草孢子进行诱变；发酵检测存活菌株的胞外虫草素和虫草多糖的含量.结果:以胞外虫草素为指标,3种诱变方式的最大正突变率分别为化学突变(29.2％)＞紫外突变(28.6％)＞复合诱变(26.5％)；以胞外多糖为指标,最大正突变率分别为紫外诱变(35.7％)＞复合诱变(33.3％)＞化学诱变(27.0％).紫外诱变突变株Z-5-1胞外虫草素产量达0.842g/L,比出发菌株高311％；紫外诱变突变株Z-4-7胞外虫草多糖产量达5.250g/L,比出发菌株高148％.在连续培养5代后,仍具有较好的遗传稳定性.紫外诱变能获得较高的蛹虫草正突变率,同时能获得高产虫草素、虫草多糖的突变株.

The aim was to obtain high-yield strains of extracellular cordycepin and polysaccharide of Cordyceps militaris. Three kind of mutation way, ultraviolet radiation (UV)、lithium chloride (LiCl) and compound mutagenesis (UV-LiCl) were used to deal with the spores of Cordyceps militaris. Fermenting the survival strains and detecting their content of extracellular cordycepin and cordyceps polysaccharide. The results showed: the maximum positive mutation rate order of extracellular cordycepin was LiCl ( 29.2%) > UV(28.6%) > UV-LiCl(26.5%) respectively, and that of extracellular polysaccharide was UV(35.7%) > UV-LiCl (33.3%) > LiCl(27.0%). The UV-induced mutant strain Z-5-1 had the highest extracellular cordycepin yield of 0.842g/L, which was 311% higher than that of the original strain. And the UV-induced mutant strain Z-4-7 had the highest extracellular Cordyceps polysaccharide production of 5.250g/L, which was 148% higher than that of the original strain. UV mutagenesis could obtain a higher positive mutation rate for Cordyceps militaris, while could produce good mutant strains with high-yield of extracellular cordycepin and extracellular cordyceps polysaccharide.