铬元素在蛹虫草中的富集及机理

Enrichment and Mechanism of Chromium in Cordyceps militaris

以新资源食品蛹虫草作为富集载体,在培养基中添加不同浓度的铬元素,探究蛹虫草的耐铬能力和富铬作用,研究铬元素对蛹虫草产量和品质的影响,并基于转录组学分析蛹虫草富铬的作用机制。结果表明,当铬元素添加浓度为400µg/mL时,蛹虫草菌丝生物量或菌落直径达到最大值,蛹虫草菌丝富铬率也最高;子实体直径、高度和生物转化率均达到最大值;添加较高浓度的铬元素后,污染率明显提高,子实体甚至发生畸变,说明过高浓度的铬元素对蛹虫草子实体的生长具有一定的胁迫作用。以普通蛹虫草和富铬蛹虫草为材料,对比分析筛选出796个差异表达基因,差异表达基因主要富集在核糖体、半胱氨酸和蛋氨酸代谢、氨基糖和核苷酸糖代谢、甲烷代谢和氨基酸生物合成5条代谢通路上。

Cordyceps militaris,a homologous new resource food,was used as the enrichment carrier,and dif⁃ferent concentrations of chromium were added into the medium to study the chrome⁃tolerance and chrome⁃rich effect of C.militaris.The effects of chromium on the yield and quality of C.militaris were discussed,and the mechanism of chrome⁃rich effect was analyzed based on transcriptomics.The results showed that when the chromium concentration was 400µg/mL,the mycelium biomass or colony diameter reached the maximum value,the chrome⁃rich rate of mycelium was the highest,and the diameter,height and biological conversion of fruiting body all reached the maximum value.However,after the addition of high concentration of chromium element,the pollution rate was significantly increased,and the fruition body even distorted,indicating that high concentration of chromium element had a certain stress effect on the growth of C.militaris.Common C.militaris and chrome⁃rich C.militaris were used as materials,and 796 differentially expressed genes were se⁃lected by comparative analysis.The differentially expressed genes were mainly enriched in five metabolic path⁃ways:ribosome,cysteine and methionine metabolism,amino sugar and nucleotide sugar metabolism,meth⁃ane metabolism,and amino acid biosynthesis.