Phenotypic Heterogeneity of autoinducer-regulated processes in Vibrio harveyi

• Applicant: Professorin Dr. Kirsten Jung
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 186440919

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.

• DFG Programme: Research Grants