细菌群体感应lux启动子的调控机制研究
时间:2019-10-17 19:27 来源:毕业论文 作者:毕业论文 点击:次
| 摘要： 群体感应现象最早是在费氏弧菌中观察到的现象，在这种费氏弧菌里群体感应掌控调节着一种生物体内可以发光的现象。对于细菌之间是否也存有信息交流，科学家提出的推断与假说如今终于被证实。这些细菌间的信息交流对人类有益或有害的关联，都值得本文去探索研究。为了研究清楚细菌群体感应发生过程中的启动机制，所以设计并进行了这次实验。实验中使用的菌种St316，St336，St346，St319来自于本实验室，实验过程利用酶标仪对各菌种的生长状况进行了荧光和光密度的检测。实验结果让本文看到，在细菌正常启动LuxR/I机制产生荧光时，crp序列对群体感应系统的LuxR/I机制有阻碍作用，所以没有crp序列的菌的荧光表达量较大。在Plux启动子无法正常启动LuxR/I机制产生荧光时，crp序列自发进行对荧光表达的另一种调控。控制条件，排除Plux启动子和crp序列对表达荧光的作用，在贫营养情况下，仅在luxbox序列作用下，启动Plux启动子表达微量的荧光。事实证明，Plux启动子与luxbox序列，crp序列共同影响并调控着细菌群体感应。 41075 毕业论文关键词： 群体感应；酶标仪；Plux启动子；crp序列；luxbox序列 Study on the mechanism of promoter regulation of bacterial quorum sensing Abstract: Quorum sensing phenomenon was first observed in Vibrio fischeri, in the Vibrio fischeri, quorum sensing regulates the luminescence phenomena from bacteria themselves .There is no information exchange between bacteria? The similar inference and hypothesis was proposed by scientists ,and now ,it is confirmed that there is the information exchange between bacteria . But at the very beginning, people thought it could not be confirmed. What is the connection between bacteria?It's all worth exploring for human beings to communicate the information between the bacteria which are beneficial or harmful.This experiment was carried out in order to study the mechanism of initiation of bacterial quorum sensing. The strains used in this experiment (St316, St336, St346, St319) are all derived from our own laboratory. In the experiment, the growth condition of each strain was detected by using microplate reader. The experimental results show that, when the bacteria normally start the LuxR/I mechanism, the crp sequence has a blocking effect on the quorum sensing system.Therefore, the lack of crp sequences of bacteria produce more fluorescence. When the Plux promoter was unable to start the LuxR/I mechanism to generate fluorescence, the crp sequence was spontaneously carried out on the fluorescence expression. Control conditions, remove the effect of Plux promoter and crp sequence on the expression of fluorescence. In the case of poor nutrition, in the role of only the luxbox sequence, the Plux promoter was activated to express a trace of fluorescence. It is proved that the Plux promoter and the luxbox sequence, crp sequence influence and regulate the bacterial quorum sensing together. Keywords: Quorum sensing; Microplate reader; Plux promoter; Crp sequence; Luxbox sequence 目录 摘要 ii Abstract ii 目录 iv 1 绪论 1 1.1 群体感应现象 1 1.1.1 群体感应的发现 1 1.1.2 群体感应的概念 1 1.1.3 群体感应的分类 1 1.1.4 群体感应的机制 2 1.1.5 群体感应的应用和研究前景 2 2 细菌群体感应lux启动子的调控机制研究方案 4 2.1 实验材料 4 (责任编辑：qin) |