蛹虫草液体种制备及发酵生产菌丝体和虫草菌素工艺优化

为获得蛹虫草液体种制备和液体发酵生产菌丝体和虫草菌素的最佳工艺,以蛹草拟青霉Peacilomyces militarisBCEC07菌株为菌种,通过对接种量(孢子浓度)的考察,探索不同孢子浓度对蛹虫草液体母种制作效果的影响;通过单因素和正交试验,优化生产虫草菌素各营养因子的最佳种类和配比。结果表明:在1.5×1010孢子数的接种量时制作的母种最适合用于蛹虫草液体发酵产菌丝体和虫草菌素;蔗糖、蛋白胨、MgSO4.7H2O、K2HPO4和NAA是最适合的碳源、氮源、无机盐及生长因子;工艺优化后得出蛹虫草液体发酵产菌丝体的最佳配方为30g/L蔗糖、25g/L蛋白胨、1.5g/L KH2PO4、0.5g/L MgSO4.7H2O和4.0mg/L NAA;产虫草菌素的最佳配方为:30g/L蔗糖、25g/L蛋白胨、1.5g/L KH2PO4、0.5g/L MgSO4.7H2O和3.0mg/L NAA。优化后生物量和虫草菌素总产量分别提高了43.00%(达31.60g/L)和31.60%(达645.12mg/L)。为进一步提高蛹虫草菌丝体及虫草菌素的单位产量提供参考。

Preparation of Liquid Seed and Optimal Fermentation Conditions for Mycelial Biomass and Cordycepin Production in Submerged Cultivation of Cordyceps militaris

In order to explore the optimal preparation method of liquid seed and fermentation conditions for mycelial biomass and cordycepin production in submerged cultivation of Cordyceps militaris(BCEC07),effect of liquid seed on mycelial growth and cordycepin production by inoculating different concentrations of spores in seed culture was investigated.Single factor tests were used to investigate the effects of medium compositions on mycelial growth and cordycepin production in liquid fermentation of C.militaris.Among these factors,sucrose,peptone,MgSO4,K2HPO4and NAA were the most suitable carbon,nitrogen and mineral sources as well as growth factors,respectively.Through orthogonal tests and the analysis of variance,the optimal liquid media was composed of 30 g/L sucrose,25 g/L peptone,0.5 g/L MgSO4.7H2O,1.5 g/L KH2PO4and 4.0 mg/L NAA for mycelial growth and 30 g/L sucrose,25 g/L peptone,0.5 g/L MgSO4.7H2O,1.5 g/L KH2PO4and 3.0 mg/L NAA for cordycepin production,respectively.This optimal liquid medium culture resulted in the yield of cordycepin up to 645.12 mg/L and the yield of mycelial biomass up to 31.60 g/L in 500 mL shake-flask culture,which revealed the enhancement by 0.316 fold and 0.43 fold compared with the basal medium.