The role of intercellular interactions in bacterial swarming motility

Brown University, Providence RI

Investigators

Abstract

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.