摘要 蝉花属虫生性药用真菌，含有多种活性成分，具有免疫调节、抗菌等生物活性和药理作用。目前国内对于蝉花的研究主要集中在其活性成分、功能评价及体外抑菌效果等方面，而对其确切的抑菌机制研究尚未见报道。因此，本研究拟以野生蝉花多糖为研究对象，研究抑菌活性，阐明其抑菌机理。本研究主要获得如下结果：88433

1。蝉花多糖对枯草芽孢杆菌具有抑菌活性，具有明显的抑菌效果

2。蝉花多糖对枯草芽孢杆菌的最小抑菌浓度（MIC）为0。003mg/mL，其抑菌率为3。7%。

3。蝉花多糖可改变枯草芽孢杆菌的生长规律，也改变了枯草芽孢杆菌的菌体细胞形态，损伤细胞膜蛋白，引起菌体壁膜的通透性变化，进而影响菌体蛋白的表达。

Abstract Cordyceps cicadae is a parasitic medicinal fungus with many active ingredients, which has attracted widespread attention due to its biological activity and pharmacological function such as the immune regulation and antimicrobial activity。  Studies on Cordyceps cicadae are mainly focused on the active ingredients, functional assessment and exosomatic antibacterial effect, but the exact antibacterial mechanism has not been reported。 The research on antibacterial activity and antibacterial mechanism of the wild Cordyceps cicadae polysaccharide were investigated in present study 。The obtained results were as follows: 

1。 Cordyceps cicadae polysaccharide showed good antimicrobial activity to Bacillus subtilis，has obvious bacteriostatic effect。

2。 The MIC of Cordyceps cicadae polysaccharide against Bacillus subtilis was 0。003 mg/mL and the corresponding antibacterial rate was 3。7 %。

3。 Cordyceps cicadae polysaccharide could change the growth curve, damage cell shapes of and the membrane proteins, change permeability of cell wall。 In addition inhibited the protein expression of Bacillus subtilis

毕业论文关键词：枯草芽孢杆菌；蝉花多糖；抑菌活性；抑菌机理

Key words: Bacillus subtilis; Cordyceps cicadae polysaccharide; antibacterial activity; antibacterial mechanism

目录

1绪论 1

1。1 蝉花简介 1

1。2蝉花多糖及其功能 1

1。3 蝉花的抑菌活性 1

1。4抑菌物质的作用机理 2

1。4。1影响细胞结构 2

1。4。2 影响细胞壁膜稳定性 2

2 蝉花多糖的提取、抑菌活性及抑菌机理研究 2

2。1实验材料与仪器 2

2。1。1。实验材料 2

2。1。2实验仪器 3

2。1。3试剂和工作液 4

2。2 实验方法 5

2。2。1蝉花多糖的提取 5

2。2。2蝉花多糖含量的测定 5

2。2。3蝉花多糖对枯草芽孢杆菌生长曲线的影响 5

2。2。4蝉花多糖最小抑菌浓度的测定 6

2。2。5蝉花多糖对枯草芽孢杆菌的结构影响 6

2。2。6蝉花多糖对枯草芽孢杆菌细胞膜稳定性的影响 6

2。2。6。1电导率测定 6

2。2。6。2菌体总蛋白源Y于Y优E尔Y论L文W网wwW.yOueRw.com 原文+QQ752018.766 分析