氯化锂诱变蛹虫草菌株液体发酵富集微量元素锌

Zinc Enrichment of Cordyceps militaris Cultured in Liquid Medium: Optimization of Medium Components and Culture Conditions and Strain Improvement by LiCl Mutagenesis

为更好地开发蛹虫草资源,以蛹虫草为富锌载体,进行发酵富锌培养条件优化,选择最佳质量分数的Li Cl诱变蛹虫草,通过火焰原子吸收法检测诱变前后菌丝体中锌元素的含量。结果表明:蛹虫草富锌的最优碳源为蔗糖,质量分数为3%,最优氮源为蛋白胨,质量分数为3%,最佳培养时间为6 d,最佳接种量为5%,最佳装液量为100 m L/250 m L,培养基中添加的最佳Zn SO4质量浓度为100μg/m L,此时,富锌率为18.54%。Li Cl的最佳诱变条件为:Li Cl质量分数0.15%。选育出富锌较高菌株5株,最高富锌率达24.68%,比出发菌株提高了近42%,具有广阔的应用前景。

In order to make better use of Cordyceps militaris,the optimization of medium components and culture conditionswas investigated for improved zinc enrichment of C.militaris in liquid-sate fermentation.Meanwhile,the optimal LiClconcentration was chosen to mutate C.militaris.Finally,zinc concentrations in the mycelia of the parental and mutant strainswere determined by graphite furnace atomic absorption spectrometry.Results showed that the optimal culture conditionsfor C.militaris to enrich zinc were as follows:3%sucrose as the best carbon source,3%peptone as the best nitrogensource,fermentation time,6d;inoculum size,5%;medium volume,100mL/250mL;and initial ZnSO4concentration,100μg/mL.Under these conditions,the rate of zinc enrichment was18.54%.The LiCl concentration of0.15%was optimalfor the mutation of C.militaris.Five strains with higher zinc enrichment ability were obtained,giving the highest rate ofzinc enrichment of24.68%,which was increased by nearly42%as compared with that of the original strain.Therefore themutants would have promising applications for industrial production.