蛹虫草对锌的耐性与富集特征

在培养基内添加不同量的锌,研究其对蛹虫草子实体的形成、子实体和菌丝体生物量、子实体多糖含量和葡萄糖含量的影响,以及蛹虫草子实体和菌丝体对锌的富集能力。结果表明锌对上述各项都有影响。液体培养条件下,锌浓度在453906mg/L范围内可以促进菌丝体生长,锌浓度超过4077mg/L时,菌丝生长受到抑制。培养基锌的浓度在4077mg/L以下时,蛹虫草菌丝体锌的富集量随着液体培养基锌浓度的提高而提高。固体培养条件下,锌含量在226453mg/kg范围内可以促进蛹虫草子实体生长,并且在此含量范围内,蛹虫草子实体中葡萄糖含量较高。培养基锌含量在680906mg/kg时,子实体多糖含量较高。培养基锌含量在2038mg/kg以下时,蛹虫草子实体中锌的富集量随着培养基锌含量的提高而提高,在培养基锌含量为2038mg/kg时,子实体中锌的含量达到28570mg/kg(干重)。

Zinc tolerance and accumulation characteristics of Cordyceps militaris

To investigate the influence of zinc on the growth and composition of Cordyceps militaris, the growth rate and the contents polysaccharide, glucose and zinc were analyzed for both mycelia and fruiting body grown in submerged culture and solid state culture supplemented with Zn2+. Here, we report that increasing Zn2+ alters the growth rate, the contents of both glucose and polysaccharide, and zinc enrichment. Our results show that zinc influences the formation of fruiting body, the biomass of fruiting body and mycelia, the contents of polysaccharide and glucose in fruiting body, and zinc enrichment in mycelia and fruiting body of C. militaris. In submerged culture, zinc at 453-906 mg/L increased mycelia growth. When higher than 4077 mg/L, zinc functions to inhibit mycelia growth. Under the concentration of 4077 mg/L, increasing the concentration of zinc in the medium could enhance the Zn2+ content in mycelia. Fruiting body growth was found increased at highest rate when the medium was supplemented with Zn2+ at 226-453 mg/kg. And the improved growth was associated with higher amount of glucose in C. militaris. The synthesis of polysaccharide increased when fruiting body of C. militaris was grown in media supplemented with Zn2+ at 680-906 mg/kg. Under the concentration of 2038 mg/kg of supplemented Zn2+, the content of zinc in fruiting body of C. militaris elevated along with increasing amount of zinc in media. The zinc content in fruiting body of C. militaris reached the highest level (28570 mg/kg (dry weight)) when 2038 mg/kg of Zn2+ was supplemented in the medium.