Proposal Number: CTS-0623870 Principal Investigator: Wolgemuth, Charles W. Affiliation: University of Connecticut Health Center Proposal Title: SGER: A two-phase fluid model of prokaryotic collective swimming
This proposal suggests the development of a two-phase fluid model to describe the pseudo-turbulent behavior that arises in dense colonies of swimming bacteria. When large populations of bacteria collectively swim, many interesting fluid flows can be generated and these counter-flows produce feedback on the swimming behavior of the bacteria. Therefore, studying the coupling between collective swimming of bacteria and the associated hydrodynamics will lead to a more complete understanding of colony development in large populations of swimming micro-organisms, such as can arise during biofilm formation. Recent experiments on dense populations of swimming Bacillus subtilis have revealed a volume fraction-dependent transition from random swimming to transient jet and vortex patterns in the bacteria/fluid mixture. This proposal will develop a model that treats the swimming bacteria as one phase of a multi-phase fluid and the surrounding water as a second-phase.
Intellectual merit: Even modest progress will greatly increase our understanding of the multiphase fluid dynamics that arises in bacterial populations, which will have consequences for other important areas of bacterial behavior such as biofilm formation. In addition, this project may provide new insights for nano- and micron-scale mixing, which could be applicable for chemical reactor applications. The project is intrinsically inter-disciplinary, drawing on ideas from fluid mechanics, applied mathematics, soft condensed matter physics, and biology.
Broader impact: The results will be broadly disseminated at interdisciplinary conferences and in interdisciplinary journals. In addition, the PI will teach methods and results from this project in an interdisciplinary upper level undergraduate/graduate class that he has developed entitled. An Introduction to Biophysics, which is cross-listed between biomedical engineering, physics, mathematics, and molecular and cellular biology. This course is taught between the Health Center campus and the main campus of the University of Connecticut.
