The role of intercellular interactions in bacterial swarming motility

非技术摘要：细菌生活在我们周围，包括我们自己的身体里。了解它们的活动能力对于控制它们以造福于我们的环境和公众健康很重要。这项研究计划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称为肠杆菌属的细菌上进行的。SM3，表现出很强的群居能力。该项目的目标是研究拥挤的细菌群体中细胞之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。了解细胞间相互作用在细菌群中的作用将有助于控制和治疗环境中的大量细菌种群，例如被称为生物膜的大片细菌，以及人类和动物肠道的微生物群。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：这项研究的目标是评估细胞间相互作用在多大程度上定义了密集细菌种群中的集群运动。该团队试图观察和表征大量细菌在适当设计的条件下的特定模式和集体运动，这些条件可以改变细胞间的相互作用，例如动态比对、流体动力学缠绕和鞭毛缠绕。他们还试图揭示由分泌的细胞外基质材料或作为粘弹性介质的添加聚合物所介导的额外相互作用。其目的是根据活性物质物理学的原理解释观察到的集体运动的模式和特征。如果成功，该计划将提供新的见解，不仅是关于细菌聚集行为的，也是关于总体上个别可移动颗粒的集体行为的。这项工作将进一步建立细菌群作为具有生物意义的活性物质，具有一系列紧急性质。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的直接影响外，这项工作还可能导致在植根于软物质物理的概念和战略指导下在生态学和感染控制方面的应用。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.