The role of intercellular interactions in bacterial swarming motility

摘要：细菌生活在我们的周围环境中，包括我们自己的体内。了解它们的活动能力对于控制它们对我们的环境和公众健康有益很重要。这个研究项目的重点是研究潮湿表面上的细菌群。这项工作是在一种新发现的细菌上进行的，这种细菌被称为肠杆菌sp. SM3，它表现出强大的群体能力。该计划的目标是研究拥挤的细菌群体中细胞间的相互作用如何影响它们的运动。细菌群将被描述为活性物质。了解细菌群中细胞-细胞相互作用的作用将有助于控制和治疗环境中大量细菌种群，例如被称为生物膜的大型细菌垫，以及人类和动物肠道中的微生物群。该项目将直接资助一篇博士论文，并为几名硕士生和本科生提供研究助理培训，其中包括一所历史悠久的黑人学院的本科生进行暑期研究。技术摘要：本研究的目的是评估细胞间相互作用在多大程度上决定了密集细菌种群的群体运动。该团队试图在适当设计的条件下观察和表征大型细菌群体的特定模式和集体运动，这些条件会改变细胞间的相互作用，例如动态排列，流体动力学夹带和鞭毛纠缠。他们还试图揭示由分泌的细胞外基质材料或添加的聚合物作为粘弹性介质介导的其他相互作用。目标是根据活性物质物理学原理来解释观察到的集体运动的模式和特征。如果成功，该项目将提供新的见解，不仅对细菌群体行为，而且对一般单个运动粒子的集体行为。这项工作将进一步确立细菌群作为具有一系列涌现特性的重要生物活性物质。该计划整合了软物质物理，微生物学和流体动力学等不同领域的知识。除了对活性物质物理研究产生直接影响外，这项工作还可能导致基于软物质物理的概念和策略在生态学和感染控制方面的应用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Abstract:Bacteria live in our surroundings, including in our own bodies. Understanding their ability to move is important for controlling them for the benefit of our environment and public health. This research program focuses on the study of swarms of bacteria on a moist surface. The work is performed on a newly discovered species of bacteria called Enterobacter sp. SM3, which manifests robust swarming abilities. The goal of the program is to examine how cell-cell interactions in a crowded population of bacteria affect their movement. The bacterial swarms will be characterized as active matter. Understanding the role of cell-cell interactions in bacterial swarms will aid in the control and treatment of large bacterial populations in environmental situations, such as large mats of bacteria known as biofilms, and in the microbiomes of human and animal intestines. The program will directly fund one PhD dissertation and provide training to several master’s and undergraduate students as research assistants, including undergraduate students from a historically black college for summer research. Technical Abstract: The goal of the study is to assess the extent to which intercellular interactions define the swarming motility in a dense bacterial population. The team seeks to observe and characterize specific patterns and collective motion of a large bacterial population under properly designed conditions that vary intercellular interactions, such as dynamic alignment, hydrodynamic entrainment, and flagella entanglement. They also seek to uncover additional interactions mediated either by secreted extracellular matrix materials or by added polymers which serve as a viscoelastic medium. The objective is to account for observed patterns and features of collective motility based on the principles of active matter physics. If successful, the program will provide new insights, not only on bacterial swarming behavior, but also on the collective behavior of individually motile particles in general. The work will further establish bacterial swarms as biologically significant active matter with a range of emergent properties. The program integrates knowledge across the diverse fields of soft matter physics, microbiology, and fluid dynamics. In addition to the direct impact on active matter physics research, the work may also lead to applications in ecology and infection control guided by concepts and strategy rooted in soft matter physics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.