目的從黃芪根、葉中分離內(nèi)生真菌,并對其抗菌、總還原力和α-葡萄糖苷酶抑制活性進行評價。方法對黃芪的根、葉進行表面消毒、無菌處理,采用組織塊培養(yǎng)分離和亞培養(yǎng)的方法分離純化黃芪根、葉內(nèi)生真菌。用形態(tài)學(xué)方法和分子生物學(xué)方法對純化后的菌落進行鑒定。對發(fā)酵液的提取物進行了抗菌、還原力和-葡萄糖苷酶抑制等多種生物活性測試。采用濾紙圓盤法對四種指示菌進行抑菌活性篩選,并測定抑菌區(qū)的直徑。采用鐵氰化鉀法和PNPG法測定了次生代謝產(chǎn)物α-糖苷酶的總還原力和抑制率。結(jié)果從黃芪根、葉中分離出72株內(nèi)生真菌。根內(nèi)生植物56種,葉內(nèi)生植物16種。這些內(nèi)生真菌首先通過研究其表面特征,然后通過分子生物學(xué)進行鑒定,并據(jù)此進行分類。抑菌區(qū)直徑表明,乙酸乙酯提取物具有較好的抑菌活性。HQ_R-PDA13對四種菌株均具有較高的抑制活性。另外四種提取物對這四種菌株都有中度抑制作用。此外,16種提取物具有一定的抗氧化活性,其中HQ_L-PDA1具有最強的還原能力。10個樣品的α-糖苷酶抑制率≥80%,最佳抑制率為HQ_R-SDA1 96.1。結(jié)論黃芪具有豐富的內(nèi)生真菌... 

【文章頁數(shù)】：70 頁

【學(xué)位級別】：碩士

【文章目錄】：
Abstract
摘要
Chapter 1 Introduction
    1.1 Literature review on Astragalus membranaceus
    1.2 Literature review on Root-Associated Bacterial diversityin Astragalus membranaceus
    1.3 Literature review on Endophytic Fungi
        1.3.1 Research status and definition of endophytic fungi
        1.3.2 Endophytic fungi-plant symbiosis
        1.3.3 Distribution of endophytic fungi in plants
        1.3.4 Biodiversity of endophytic fungi in plants
        1.3.5 Bioactivities of secondary metabolites isolated from endophyticfungi of medicinal plants
            1.3.5.1 Antimicrobial activities of microbial secondary metabolites
            1.3.5.2 Antioxidant activities of microbial secondary metabolites
            1.3.5.3 Inhibition ofα-glucosidase activities of microbial secondary metabolites
            1.3.5.4 Anti-cancer activities of microbial secondary metabolites
    1.4 Problems and prospects of secondary metabolites of endophytic fungi research
    1.5 Research content,purpose and significance
Chapter 2 Preliminary examination of the Endophytic bacterialComposition of Astragalus membranaceus
    2.1 Test materials
        2.1.1 Plant and soil samples
    2.2 Test method
        2.2.1 Sampling of plant and soil
        2.2.2 Characterization of soil sample
        2.2.3 High-thorough sequencing
        2.2.4 Bioinformatic analysis
    2.3 Results and discussion
        2.3.1.Physicochemical properties of the soil
        2.3.2.Diversity of the bacterial community
        2.3.3.Effects of soil physic-chemical factors on bacterialcommunity composition
        2.3.4.Analysis of the correlation of bacterial communities
    2.4 Discussion
    2.5 Summary
Chapter 3 Isolation and purification of endophytic fungi fromAstragalus membranaceus
    3.1 Test material
        3.1.1 Plant sample
        3.1.2 Reagents
        3.1.3 Instruments/Apparatus
        3.1.4 Culture media composition
    3.2 Test method
        3.2.1 Isolation and purification of endophytic fungi
        3.2.2 Preservation of endophytic fungi
        3.2.3 Morphological identification of endophytic fungi
        3.2.4 Molecular identification of endophytic fungi
    3.3 Results and Discussion
        3.3.1 Isolation,purification and preservation of endophytic fungi
        3.3.2 Morphological characteristics of endophytic fungiisolated from Astragalus membranaceus
            3.3.2.1 Growth pattern and surface morphology characteristics
            3.3.2.2 Microscopic identification of endophytic fungi isolatedfrom Astragalus membranaceus
        3.3.3 Molecular biology identification of endophytic fungi isolated fromAstragalus membranaceus
    3.4 Summary
Chapter 4 Antibacterial activities of secondary metabolitesisolated from endophytic fungi of Astragalus membranaceus
    4.1 Test Material
        4.1.1 Test strains
        4.1.2 Culture medium
        4.1.3 Reagents
        4.1.4 Instruments/Apparatus
    4.2 Test method
        4.2.1 Culture and fermentation of endophytic fungi
        4.2.2 Antibacterial activity test
    4.3 Results and Discussion
    4.4 Summary
Chapter 5 Antioxidant andα-glucosidase inhibition activity of secondaryMetabolites isolated from endophytic fungi of Astragalus membranaceus
    5.1 Test Materials
        5.1.1 Test samples
        5.1.2 Reagents
    5.2 Test method
        5.2.1 Determination of Total Reduction Force
        5.2.2 Screening ofα-glucosidase inhibition activity
    5.3 Results and Discussion
        5.3.1 Total Reductive Force
        5.3.2 Inhibition ofα-glucosidase
Discussion
Conclusion
References



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