Phenotypic Heterogeneity of autoinducer-regulated processes in Vibrio harveyi

细菌产生和分泌信号分子，即所谓的自动诱导器(AIS)，使它们能够在最广为人知的群体感应过程中监控自己的种群密度和/或环境。该项目将探索哈维氏弧菌(Vibrio Harveyi)依赖AI过程表型异质性的分子基础，哈维氏弧菌是群体感应方面研究最好的模式生物之一。这种细菌以依赖于人工免疫的方式产生生物发光、外酶、铁载体、生物膜和III型分泌系统。我们在AI激活的野生型哈维氏弧菌群落中发现了生物发光产生的表型异质性。重要的是，异质种群具有更高的生物被膜能力。本项目的目标是通过以下研究来研究这些现象的分子细节：1.在生长成生物膜的浮游细胞中，各种AI调控表型的时空表现；2.调节HAI-1、AI-2和AI-1三种AI有效浓度的分子成分；3.在复杂的信号转导级联中负责(双)多稳定性的分子开关；以及4.使用系统方法在细菌种群中的工作分工。解决这些问题将提高我们对与医疗和生物技术应用相关的细菌种群发展的理解。

Bacteria produce and excrete signaling molecules, so called autoinducers (AIs), which allow them to monitor their population density and/or their environment in a process best known as quorum sensing. The project will explore the molecular basis of phenotypic heterogeneity of AIdependent processes in Vibrio harveyi, one of the best investigated model organism in quorum sensing. This bacterium produces bioluminescence, exoenzymes, siderophores, biofilm, and a type-III secretion system in an AIs-dependent manner. We found phenotypic heterogeneity within an AI-activated wild-type community of V. harveyi with respect to bioluminescence production. Importantly, a heterogeneous population had a higher capacity to produce biofilm. It is the goal of this project to investigate the molecular details of these phenomena by studying: 1. the spatiotemporal appearance of various AI-regulated phenotypes in planktonic cells growing into a biofilm; 2. the molecular components that program the available concentration of the three AIs HAI-1, AI-2 and CAI-1; 3. the molecular switches responsible for (bi-) multi-stability within the complex signal transduction cascade; and 4. the division of work within a bacterial population by using systemic approaches. Solving these questions will improve our understanding of the development of bacterial populations which is relevant for medical and biotechnological applications.