锌富集对蛹虫草菌丝体内虫草素、腺苷含量的影响

为了解蛹虫草菌丝体对锌的富集特性,研究锌富集对蛹虫草菌丝体内虫草素、腺苷含量的影响,通过在液体培养基中添加不同质量浓度的锌离子(0~35 g/L),探讨其对蛹虫草菌丝生物量、菌丝体内锌积累量,以及锌的富集对菌丝体内虫草素、腺苷含量产生的影响。结果表明:在0~35 g/L锌离子的梯度范围内,蛹虫草菌丝生物量与锌质量浓度呈显著负相关,锌质量浓度35 g/L为蛹虫草菌丝生长极限浓度。锌质量浓度40.0 g/L及以上菌丝生长受到完全抑制。菌丝体内锌的积累量随锌质量浓度的增加而显著升高,锌质量浓度为35.0 g/L时锌积累量可达到193.87 mg/g(干重)。蛹虫草菌丝体内腺苷的含量随锌质量浓度的增加而降低,在锌质量浓度为5 g/L时降幅显著,腺苷含量仅为对照组的17.24%,之后腺苷含量变化趋势趋于水平。腺苷含量的降低可能是因为锌的富集干扰了蛹虫草菌丝体内初生代谢的正常进行。虫草素的含量随锌质量浓度的增加而显著降低,可能是由于其直接前体腺苷含量的降低,或是Zn离子的加入,使得某些被刺激的酶和基因通过转录因子影响了虫草素的合成。

Effect of Zinc Accumulation on Cordycepin and Adenosine Content in Mycelia of Cordyceps militaris

To research the characteristics of zinc accumulation, the effects of zinc accumulation on cordy- cepin and adenosine content in Mycelia of Cordyceps militaris were studied. The mycelial biomass, Zn ac- cumulation, and cordycepin and adenosine content in mycelia of C. militaris with submerged culture supplemented with Zn2 ＋ concentrations from 0 to 35 g/L decreased. The mycelial biomass of C. mili- taris was negatively correlated with zinc concentration, and the upper limit of Zn2 ＋ concentration for mycelial growth was 35 g/L. At the Zn2 ＋ concentration of 40 g/L or above, the mycelial growth was completely inhibited. The zinc content in mycelia increased significantly with the increase in Zn2 ＋ con- centration in the culture medium, up to 193.87 mg/g zinc content based on the dry weight of mycelia was approached when the zinc concentration in the culture medium was 35 g/L. The adenosine content in mycelia decreased with the increase of the concentration of zinc. The adenosine content was only 17.24%of the control group, and then the trend tended to level. Adenosine content reduced, probably because zinc accumulation interfered with the normal work of primary metabolism in Mycelia of Cordyceps mili- taris. The cordycepin content in mycelia declined significantly with the increase of Zn2 ＋ concentration in the culture medium, probably because adenosine content （its direct premise） decreased or zinc ion was added, which made some stimulated enzymes and genes affected the synthesis of cordycepin by transcrip- tion factors.