一株胜红蓟内生真菌Letendraea sp.WZ07的鉴定、培养条件与抗氧化活性  

Identification of endophytic fungi Letendraea sp.WZ07 from Ageratum conyzoides and its fermentation extract antioxidant activity

作　　者：乔自鹏 张君毅[1] 王明元[1] 刘建福[1] 王奇志[1] QIAO Zipeng;ZHANG Junyi;WANG Mingyuan;LIU Jianfu;WANG Qizhi(College of Chemical Engineering,Huaqiao University,Xiamen 361021,China)

机构地区：[1]华侨大学化工学院,厦门361021

出　　处：《应用与环境生物学报》2021年第2期449-458,共10页Chinese Journal of Applied and Environmental Biology

基　　金：2018年中医药公共卫生服务补助专项(财社[2018]43号);福建省农业重点自然科学基金项目(2014N0026);泉州市校(院)地协同创新专项(重点)项目(2014Z101);华侨大学研究生科研创新基金项目(18014087015)资助。

摘　　要：对从药用植物胜红蓟茎部组织中分离获得的一株内生真菌进行形态学与ITS分类学鉴定;采用单因素实验及正交设计优化该菌株生长的最适条件;探究发酵液不同极性提取物(乙酸乙酯提取物EAE、乙醇提取物EE和石油醚提取物PEE)黄酮、多酚含量与其体外抗氧化活性[1,1-二苯基-2-三硝基苯肼(DPPH)、2,2’-二氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)自由基清除能力和Fe^(3+)还原能力]的相关性.该菌株为Letendraea sp.WZ07;WZ07菌丝生长的最适条件为温度为28℃,pH为5.0,淀粉20 g/L,尿素0.5 g/L,磷酸二氢钾1 g/L,硫酸镁0.5 g/L,VB6或肌醇10 mg/L;3种有机溶剂提取物黄酮和多酚含量差异显著(P<0.05),其中EAE含有的黄酮和多酚含量最高,分别为11.97 mg/g、14.70 mg/g;提取物均具有清除DPPH、ABTS自由基和还原Fe^(3+)的能力,且均呈量效关系,EAE抗氧化活性能力最强,在浓度为2mg/mL时,对清除DPPH自由基率可达87.23%,其IC_(50)为242.13μg/mL;清除ABTS自由基率为94.72%,与阳性组维生素C清除能力相当,其IC_(50)为58.38μg/mL;Fe^(3+)还原力OD值为0.78,其IC_(50)为325.17μg/mL.相关性分析显示不同提取物的黄酮和多酚含量均与抗氧化活性呈正相关关系,表明黄酮和多酚类成分可能是WZ07菌株起抗氧化活性的功效因子.(图7表10参51)In this study,a pure culture strain(WZ07)from the stems of the medicinal plant Ageratum conyzoides L.was obtained using tissue separation and purification methods.Taxonomic characteristics were determined based on morphological and ITS sequence analyses.Optimal culture conditions of mycelia were evaluated based on their growth in different media.The correlation between the in vitro antioxidant activity(DPPH radical scavenging,ABTS radical scavenging,and Fe^(3+)reducing power assays)and the content of flavonoid and polyphenol compounds in the different polar extracts of fermentation broth(ethyl acetate extract EAE,ethanol extract EE,and petroleum ether extract PEE)were studied.The results showed that the strain was classified as Letendraea sp.WZ07.The optimal conditions for mycelial growth were temperature of 28℃,pH of 5.0,C/N ratio of 30/1,20 g/L starch,0.5 g/L urea,1 g/L potassium dihydrogen phosphate,0.5 g/L magnesium sulfate,and 10 mg/L VB6 and inositol.The flavonoid and phenolic contents in the three organic solvent extracts significantly differed(P<0.05),of which EAE had the highest content of flavonoids(11.97 mg/g)and polyphenols(14.70 mg/g).The antioxidant assays indicated that the extracts of different organic solvents had the ability to scavenge DPPH and ABTS free radicals and reduce Fe^(3+)and showed a dose–effect relationship,of which EAE had the strongest antioxidative activity.At the concentration of 2 mg/mL,the DPPH scavenging ability was 87.23%(IC_(50)=242.13μg/mL),and the ABTS scavenging ability was 94.72%(IC_(50)=58.38μg/mL),which was equivalent to the ascorbic acid(VC)scavenging ability in a positive group.The OD value for Fe^(3+)reducing power was 0.78(IC_(50)=325.17μg/mL).The correlation analysis revealed that the flavonoid and phenolic contents were positively correlated with antioxidant activity in the different extracts,which indicated that flavonoids and polyphenols were the dominant antioxidant factors.The results of this study provide a scientific basis for the development and uti

关 键 词：胜红蓟 内生真菌 分离鉴定 培养条件 黄酮 多酚 抗氧化活性 

分 类 号：Q949.32[生物学—植物学] S567.219[农业科学—中草药栽培]