基于氧化应激反应提高蛹虫草中虫草素产量的激发子筛选及发酵条件优化  

Screening of Elicitors and Optimization of Fermentation Conditions for Enhancing Cordycepin Production in Cordyceps militaris Based on Oxidative Stress

作　　者：王晓玉 于金艳 罗佳豪 姜文明 韩春超[1] WANG Xiaoyu;YU Jinyan;LUO Jiahao;JIANG Wenming;HAN Chunchao(College of Pharmacy,Shandong University of Traditional Chinese Medicine,Jinan,Shandong 250355)

机构地区：[1]山东中医药大学药学院,山东济南250355

出　　处：《北方园艺》2022年第16期113-120,共8页Northern Horticulture

摘　　要：以蛹虫草为试材,以虫草素含量为评价指标,在单因素试验的基础上,采用响应面设计试验优化添加抗氧化剂后的蛹虫草液体发酵条件,并对发酵体系中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)及过氧化氢酶(CAT)活性进行测定,研究了抗氧化剂的加入对发酵体系代谢的影响,以期提高蛹虫草液体发酵虫草素产量,并对抗氧化物质的加入与关键氧化还原酶活性及菌体形态的关系进行初步探究。结果表明:选择Na_(2)SO_(3)作为抗氧化添加物,发酵时间定为28 d,响应面试验得到最佳发酵条件为Na_(2)SO_(3)添加量10.2 mg·mL^(-1)、发酵温度24.3℃、初始pH 7.78,发酵得到胞外虫草素产量1188.165μg·mL^(-1),增加达55.16%;添加Na_(2)SO_(3)使SOD、GSH-Px活性显著增强,其中GSH-Px活性增加达47.51%;此外,扫描电镜显示该条件下,菌体形态发生明显改变,内部结构由疏松多孔变得致密。初步证明加入抗氧化物质能够调节发酵体系氧化应激进而影响虫草素代谢。Cordyceps militaris was used as the test material,on the base of single factor experiment,the response surface design experiments were used to optimize the liquid fermentation conditions of Cordyceps militaris after adding antioxidants while the content of cordycepin was taken as the evaluation index.And the activities of glutathione peroxidase(GSH-Px),superoxide dismutase(SOD)and catalase(CAT)in the fermentation system were also measured to investigate the effect of antioxidants on the metabolism of the fermentation system,in order to improve cordycepin yield in liquid fermentation of Cordyceps militaris,and to explore the relationship between the addition of antioxidant substances and the activity of pivotal oxidoreductase and mycelial morphology.The results showed that Na_(2)SO_(3) was selected as the antioxidant additive,and the fermentation time was set as 28 days.The response surface experiments showed that the optimal fermentation conditions were Na_(2)SO_(3) addition of 10.2 mg·mL^(-1),fermentation temperature of 24.3℃,and initial pH of 7.78.The content of extracellular cordycepin was 1188.165μg·mL^(-1),which increased by 55.16%compared with blank group.The results of enzyme activity assay demonstrated that the addition of Na_(2)SO_(3) significantly enhanced the activities of SOD and GSH-Px,especially that of GSH-Px increased by 47.51%.Furthermore,scanning electron microscopy showed that the morphology of the mycelium changed obviously,and the interior structure changed from porous to dense under the optimal conditions.The results suggested that the addition of antioxidant could regulate the oxidative stress in the fermentation system and then affect the metabolism of cordycepin.

关 键 词：蛹虫草 虫草素 氧化应激 氧化还原酶 菌体形态 

分 类 号：S567.35[农业科学—中草药栽培]