摘要：近几年，内生真菌逐渐成为了人们研究的热点。内生真菌资源丰富，能够产生具有新颖的结构和生理活性的代谢产物。内生真菌代谢产物的抑菌活性近年来受到了人们的关注，但到现在为止内生真菌抑制携带β-内酰胺酶基因的细菌菌株的研究鲜有报道。本研究以课题组分离筛选获得的一株内生真菌为材料，对其代谢产物进行初步的抑菌活性研究。首先将获得的内生真菌菌株进行液体培养，然后将发酵液粗提物对携带β-内酰胺酶基因重组质粒的菌株、耐甲氧西林金黄色葡萄球菌等耐药菌株及野生型金黄色葡萄球菌、枯草杆菌及大肠杆菌进行抑菌实验。实验结果表明：提取物对测试的20种携带临床危害严重的β-内酰胺酶基因的菌株均有抑制作用，对其中18株细菌的MIC等于或低于2.5 mg/ml，对另外2株细菌（A10和A11）的MIC为5mg/ml。提取物对耐甲氧西林金黄色葡萄球菌的MIC为10.0mg/ml，对野生型枯草杆菌的MIC为1.3mg/ml,对野生型大肠杆菌和金黄色葡萄球菌的MIC为5.0mg/ml。本研究为从该菌株中开发抗菌药物提供了依据及基础数据。69051

毕业论文关键词：内生真菌、代谢产物、抑菌活性、β-内酰胺酶、耐甲氧西林金黄色葡萄球菌

Study on the antibacterial activity of an endophytic fungus

Abstract: In recent years, endophytic fungi have gradually become a hot research topic. Endophytic fungi are rich in resources and can produce metabolites with novel structures and physiological activities. The antimicrobial activity of endophytic fungal metabolites has received growing attentions in recent years. However up to now, the research on endophytic fungi inhibiting the bacterial strains carring beta-lactamase genes is rarely reported. In this study, a strain of endophytic fungus isolated by the research group was studied on the antimicrobial activity. The endophytic strains was cultured in PD liquid medium, the antibacterial activity of the metabolite extract of the strains was conducted. The tested bacterial strains included those carried beta-lactamase genes, Methicillin-resistant Staphylococcus aureus (MRSA), wide type S. aureus, Bacillus subtilis and Escherichia coli. The results showed that:1.the extract has inhibitory effect on all the test strains with beta-lactamase genes which is clincal hazard. The MIC of the extract on 18 strains among them is equal to or less than 2.5mg/ml,The MIC on the rest strains is 5mg/ml. The MIC of extract on MRSA and B. subtilis is 10.0 and 1.3mg/ml, respectively.  The MIC on E. coli and S. aureus is 5.0mg/ml. This study provided basic data for the development of antibacterial drugs from the endophytic strain.

Keywords:Endophytic fungi; Metabolic product; Bacteriostatic activity; beta-lactamase;  MRSA

目录

引言 5

一 材料与方法 6

1.1材料 6

1.2仪器 6

1.3试剂与培养基 6

1.3.1试剂 6

1.3.2培养基 6

1.4实验方法（微量肉汤二倍稀释法） 6

二、实验结果： 8

2.1提取物的pH 值 8

2.2提取物对携带β-内酰胺酶基因重组质粒的菌株的抑制作用 8

2.3提取物对MRSA、野生型金黄色葡萄球菌、枯草杆菌及大肠杆菌的抑制作用 9

讨论 10

致谢