【作者】 庞蕾；

【导师】 严铸云；

【作者基本信息】 成都中医药大学 ， 生药学， 2005， 硕士

【摘要】 内生真菌是指那些在其生活史中的某一段时期生活在植物组织内,对植物组织没有引起明显病害症状的真菌。近年来的研究表明,内生真菌可以产生与宿主相同或相似的代谢产物。此特性使植物内生真菌成为从中寻找结构新颖、活性专一的重要化合物的新资源。由此,本课题选择了银杏Ginkgo biloba L.和厚朴Magnolia officinalis Rehd. et Wils.为代表材料,开展了两种植物内生真菌的微生物学研究;银杏中具内酯活性的菌株筛选研究;厚朴中具抑菌活性的菌株筛选研究;厚朴中活性菌株的物质基础研究等工作。 从四个不同来源的银杏根及茎中,共分离出178株内生真菌,经形态观察鉴定为1纲、4目、6科、28属。在目的分类水平上以丛梗孢目(Moniliales)为优势种群;在属的分类水平上以镰孢属(Fusarium)、曲霉属(Aspergillus)、枝孢属(Cladosporium)为优势种群。实验发现,银杏不同部位的内生真菌数量及种类分布差异较大,不同来源的银杏也有类似情况。体现出银杏内生真菌的多样性、组织专一性。就上述178株真菌发酵液进行内酯类物质TLC检测,发现36株与银杏内酯C斑点颜色一致,R_f值接近.将这36株发酵液进行抑制血小板聚集实验,发现有14株能够有效抑制ADP引起的血小板聚集,其中的7株被认为能够产生银杏内酯C或其结构类似物。 首次从两个不同来源的厚朴茎中分离出48株内生真菌,经形态观察鉴定为1纲、3目、6科、16属。在目的分类水平上以丛梗孢目(Moniliales)为优势种群;在属的分类水平上以曲霉属(Aspergillus)、青霉属(Penicillium)和镰孢属(Fusarium)为优势种群。不同来源的厚朴内生真菌数量及种类分布差异较大。就上述内生真菌中的27株进行厚朴酚、和厚朴酚HPLC检测,发现17株真菌菌丝或发酵液中含有厚朴酚、和厚朴酚或其结构类似物。另将27株真菌的发酵液进行金黄色葡萄球菌(Staphylococcus aureus)、大肠杆菌(Escherichia coli)、绿脓杆菌(Pseudomonas aeruginosa)3种人类病原细菌的抑菌实验,结果表明其中的7株真菌发酵液对金黄色葡萄球菌(Staphylococcus aureus)、大肠杆菌(Escherichia coli)有不同程度的抑制作用,用不同培养基进行复筛后,选择抑菌作用较强的FM044进行抑菌活性物质基础研究。从中分离出一种白色晶体,经IR、MS、~1H-NMR波谱分析鉴定为D-甘露醇(mannitol)。抑菌活性物质基础研究仍在进行。更多还原

【Abstract】 Endophytes are referred to fungi colonizing healthy plant tissues without causing overt symptoms in or apparent injury to the host. Research results in near years show that endophyte can produce some metabolites similar to those from the host plant. This feature could make endophyte became a new resource which can produce some compounds with novel structure and specific bioactivity. For above reasons we selected Ginkgo biloba L. and Magnolia officinalis Rehd. et Wils. as our original materials, to isolate and identify their endophytic fungi, and sift out the bioactive strains from them. Meanwhile, we studied the bioactivities of one bioactive strain in initial stage. According to our research findings, we concluded the above contents as following:Firstly, 178 strains endophytes were isolated from the roots and stems of Ginkgo biloba L. and they were morphologically identified belonging to 28 genera, 6 families, 4 orders and 1 class. Moniliales, which includes 96.6% of the whole strains, is believed the dominant order. While Fusarium, Aspergillus, Cladosporium are believed the dominant genera, which may include 36.5%, 19.7%, 10.1% of the whole strains in respective. It is shown that quantity, species and distributing of the endophytic fungi are varied in different organs of Ginkgo biloba L. Meanwhile, we used TLC method in order to compare the metabolites of 178 strains with terpenoids lactone and the result shows that the metabolites of 36 strains may include terpenoids lactone. On the other hand, the result of inhibition against platelet aggregating experiment proves that 7 strains may produce ginkgolide C or similar compounds.Secondly, 48 strains endophytes were isolated from the stems of Magnolia officinalis Rehd. et Wils. As a result, they were morphologically identified belonging to 16 genera, 6 families, 3 orders and 1 class. Moniliales, which includes 83.3% of the whole strains, is believed the dominant order. While Aspergillus, Penicillium, Fusarium are believed the dominant genera, which include 31.3%, 18.8%, 14.6% of the whole strains separately. It is also shown that quantity, species and distributing of the endophytic fungi are varied in different habitat of Magnolia officinalis Rehd. et Wils. The result of the HPLC experiment to metabolites of 27 strains indicates the mycelium or fermented liquid of 17 strains may include honokiol, magnolol or similar compounds. In addition, the result of antibacterial assay shows that 7 strains of the fungi have antagonism against one or more bacteria, such as Staphylococcus aureus, Escherichia coli, Pseudominas aeruginosa. After repeatedly sifted, we selected FM044, which had better antibacterial effect, to study antibacterial compounds. By this process, a crystal was isolated from the mycelium of FM044 and its structure was identified as D-mannitol by some structure analysis methods as IR, MS, ~1H-NMR. Further study on the antibacterial bioactivities is still in continuing.更多还原