谷胱甘肽促进液体发酵体系中蛹虫草合成虫草素

虫草素是药用真菌蛹虫草Cordyceps militaris的主要活性成分,具有抗癌、抗肿瘤、抗病毒等多种生理活性。研究表明,氧化应激参与丝状真菌的次级代谢调控,然而在蛹虫草虫草素代谢中尚未见报道。本研究以蛹虫草深层液体发酵体系为研究对象,添加谷胱甘肽（glutathione,GSH）调节细胞氧化还原状态,考察其对虫草素代谢的影响。添加3.0g/L GSH,发酵20d虫草素产量达到(439.69±12.43)mg/L,较无添加对照组提高471.24%,同时谷胱甘肽过氧化物酶（glutathione peroxidase,GPX）活力提高414.82%;基因表达分析显示,添加GSH后虫草素生物合成关键基因Cns1和Cns2表达显著上调,发酵第15天其表达量分别是对照组的540.67倍和25.81倍。研究结果初步证实,氧化应激参与蛹虫草中虫草素代谢调控。

Enhancement of cordycepin biosynthesis by glutathione supplementation during liquid fermentation of Cordyceps militaris

Cordycepin is the main active ingredient of the medicinal fungus C.militaris, with a variety of physiological functions such as anti-cancer, anti-tumor and anti-virus activity. Oxidative stress was shown to be involved in the regulation of secondary metabolism of filamentous fungi, however, the relationship between oxidative stress and the regulation of cordycepin metabolism inC.militaris has not yet reported so far. In this study, to investigate the influence of oxidative stress on cordycepin metabolism, glutathione (GSH), as the antioxidant for regulating cellular redox state, was supplemented during liquid submerged fermentation of C.militaris. The experimental data showed that the yield of cordycepin could reach (439.69±12.43)mg/L in 20 days when 3.0g/L GSH was added to the medium, 471.24% higher than that of the control (without addition of GSH). The activity of glutathione peroxidase (GPX) increased by 414.82% as compared with the control. The relative gene expression levels ofCns1 and Cns2 indicated by qRT-PCR were significantly up-regulated by supplementation of GSH, increasing by 540.67 times and 25.81 times as compared with the control in 15 days, respectively. The experimental results preliminarily show that the regulation of cordycepin metabolism is coupled with oxidative stress inC.militaris.