摘要目标：本研究旨在设计并建立一个有效的群体感应模型并由此模型来分析物质的群体感应抑制活性，从而筛选出有效的群体感应抑制剂。

方法和结果：紫色色杆菌CV026，一种Tn-5突变株，作为一个指标来监测群体感应抑制，发现其能较好的符合要求，除此之外，我们也采用野生菌ATCC12472来监测群体感应抑制,但效果不如CV026明显。待测物如白藜芦醇，鹅掌楸CH2Cl2提取部位或其他植物提取物，加到紫色色杆菌CV026培养基中。其抑制活性是通过所呈现的白色晕圈大小与酶标仪下测得的紫色杆菌素的产量而确定的。结果表明，白藜芦醇与鹅掌楸二氯甲烷提取部位会以溶度依赖方式显著降低紫色杆菌素产量，这就是紫色色杆菌的群体感应调节行为，而所测试的四组植物提取物样品未发现明显群体感应抑制活性。63951

结论: 白藜芦醇与杂交鹅掌楸的二氯甲烷提取部位可以抑制细菌的群体感应，但高溶度的白藜芦醇为抑菌效果，而另外四组植物提取物样品不能抑制细菌群体感应。

这项研究的意义和影响: 结果表明一些植物提取物活性成分（如白藜芦醇）可能干扰细菌的群体感应系统,调控其相关功能和防止细菌致病。进一步的研究要做的就是在我们的实验室中，从提取物中分离出特定的化合物,评估它们作为群体感应抑制剂和分析其确切的作用机制。

毕业论文关键词：  群体感应抑制   紫色色杆菌CV026   筛选

 毕业设计说明书（论文）外文摘要

Title: The construction of the quorum-sensing model for screening  quorum sensing inhibitors

Abstract Aims: This study aimed to construct an effective quorum sensing model and using this model to screen some natural products as quorum-sensing inhibitors.

Methods and results: We use Chromobacterium violaceum CV026, a double mini-Tn5 mutant, as an indicator to monitor quorum-sensing. In addition, we also adopt wild bacteria ATCC12472 as the indicator to control quorum-sensing. Under this bio-guided assay, some natural products such as resveratrol，liriodendron dichloromethane extraction part or other plant extracts were tested, then add to C.violaceum CV026 medium. Inhibitory activity was presented through the white halo and measured by quantifying violacein production using a microplate reader. The results showed that resveratrol and liriodendron dichloromethane extraction part could significantly reduce violacein production in a concentration-dependent manner, and four other plant extracts showed no obvious quorum-sensing inhibitory activity.

Conclusion: Resveratrol and CH2Cl2 extract from Liriodendron hybrid could inhibit bacterial quorum sensing, but high solubility of resveratrol has bacteriostatic effect, while the other four plant extracts samples can't inhibit bacterial quorum sensing.

Significance and impact of the study: the results showed that the activity of some plant extracts ingredients (such as resveratrol) may interfere with the bacterial quorum sensing system, regulate the related function and prevent bacterial pathogenesis. Further research, such as isolation of QS inhibitors and the mechanism of QS inhibiting.

Keywords : C.violaceum CV026 , Quorum-sensing inhibitory , Screening .

 目 录

1  绪论 1

1.1 细菌的QS系统分类 1

1.1.1 革兰氏阳性菌的QS系统 1

1.1.2 革兰氏阴性菌的QS系统 1

1.1.3 G-与G+菌共有的QS系统 2

1.1.4 其他的群体感应系统 2

1.2几种典型的QS系统细菌