Elucidating mechanisms of acetylcholine signaling in bacterial biofilms

项目摘要 虽然微生物是单细胞生物，但它们自然形成密集的群落，称为生物膜。 生物膜构成了一个重大的公共卫生挑战，因为它们经常导致难以治疗的感染， 抗生素的耐药性和持久性等特性，即使是长疗程的抗生素。以来 微生物学研究通常在受控实验室下使用驯化菌株进行 在生物膜不形成的条件下，有必要了解只存在于生物膜中的紧急行为。 生物膜将细菌基因调控和代谢与生物膜形态和行为相结合需要一种 具有充分映射的遗传和代谢途径的模型系统，建立遗传易处理性，以及 已知的生物膜生长条件。由于这些原因，枯草芽孢杆菌被认为是生物膜的模式生物 问题研究枯草芽孢杆菌生物膜是由一个由常驻细胞和严格调控的细胞外膜组成的网络 矩阵初始生物膜形成和基质表达受主调节因子的表达控制， 对传统的群体感应分子有反应。然而，芽孢杆菌中新发现的基于离子的信号传导， 枯草芽孢杆菌通过协调生物膜内的营养共享而对群落水平的适应性至关重要。这一发现 强调了对生物膜的形成和整体适应性至关重要的信号通路， 未被发现为了帮助缩小这一知识差距，我们将专注于发现合成基因， 乙酰胆碱和基于乙酰胆碱的细胞间信号传导表型。我们的主要假设是乙酰胆碱 在生物膜内的细胞间通讯中作为信号分子。目的1将确定乙酰胆碱生物膜 使用显微镜和Aim 2的信号表型将鉴定负责乙酰胆碱合成的基因。 这个项目的首要目标是提供遗传、代谢和生理的第一个描述。 乙酰胆碱在所有细菌中的作用机制。此外，合成基因的功能 负责乙酰胆碱生产将为科学界提供基础知识， 探索其他物种中的细菌同源物，以及细菌内的信号传导如何影响复杂系统 就像发育和疾病中的肠脑轴一样。

Project Summary While microbes are single-celled organisms, they naturally form densely packed communities known as biofilms. Biofilms pose a major public health challenge as they often cause difficult-to-treat infections that exhibit properties such as antimicrobial resistance and persistence even with long courses of antibiotics. Since microbiology research has often been conducted using domesticated strains under controlled laboratory conditions where biofilms do not form, there is a need for understanding emergent behavior that only exists in biofilms. Integrating bacterial gene regulation and metabolism with biofilm morphology and behavior requires a model system with sufficiently mapped genetic and metabolic pathways, established genetic tractability, and known biofilm growth conditions. For these reasons, Bacillus subtilis is considered a model organism for biofilm studies. Bacillus subtilis biofilms are composed of a network of resident cells and tightly regulated extracellular matrix. Initial biofilm formation and matrix expression is controlled by the expression of master regulators that respond to traditional quorum-sensing molecules. However, newly appreciated ion-based signaling in Bacillus subtilis is critical for community level fitness by coordinating nutrient sharing within a biofilm. This discovery highlights signaling pathways that are critical for the formation and overall fitness of biofilms yet remain undiscovered. To help close this gap in knowledge, we will focus on discovering the synthesis genes for acetylcholine and acetylcholine-based cell-to-cell signaling phenotypes. Our leading hypothesis is acetylcholine acts as a signaling molecule in cell-to-cell communications within biofilms. Aim 1 will identify acetylcholine biofilm signaling phenotypes using microscopy and Aim 2 will identify the genes responsible for acetylcholine synthesis. The overarching goal of this project is to provide the first description of genetic, metabolic, and physiological mechanisms for acetylcholine in all bacterial species. Additionally, the function of and synthesis gene(s) responsible for acetylcholine production will provide the scientific community with the foundational knowledge to explore bacterial homologs in other species and how signaling within bacteria may also impact complex systems like the human gut-brain-axis in development and disease.