CAREER: Bacterial upstream swimming in self-regulating flow networks

Bacteria have the remarkable ability to swim upstream. This motion against fluid flows, called rheotaxis, enables bacteria to invade anatomical tracts and biomedical devices. Upstream swimming can lead to conditions including urinary tract infections and the contamination of catheters. This CAREER project will use experiments and modeling to reveal how bacteria can swim upstream against flows, how bacteria can navigate in complex flow networks, and how microbial communities can gain control over their hydrodynamic environments. Importantly, this project will also show how these processes can be controlled and prevented. This work is timely because it is estimated that by the year 2050, microbes will kill more people than cancer. Moreover, this research will elucidate how microbial consortia can help improve soil quality and suppress crop diseases. As such, this project unites the disciplines of microbiology, engineering, medicine, and agriculture. To connect this research with a broader community, the project includes the development of a course about “Culinary Fluid Mechanics and Science Communication,” where undergraduates will teach basic science concepts at high school using live demonstrations that can be performed with affordable kitchen equipment and cooking ingredients. To develop a fundamental and quantitative understanding to predict and control bacterial upstream swimming, this project will combine techniques from biophysics, microbiology, holographic 3D microscopy, nanofabrication, and network theory. The project will: (1) Determine the ability of bacteria to invade upstream in nanofabricated flow networks; (2) Tune multi-species bacterial interactions in mazes with dynamical microgradients; and (3) Uncover the rules governing self-regulation of microbial communities in adaptive flow networks. Hence, this award will unravel how the microstructure of flow networks can promote or inhibit rheotaxis, how cells navigate in biochemical landscapes subject to currents, how bacteria can reshape their hydrodynamic surroundings, and how this knowledge can be used to control bacterial transport. Results from this work can contribute to inhibiting infections caused by bacteria and other pathogens and provide new strategies to stop the contamination of biomedical devices. More generally, the coupling between microbes and flows is essential in numerous applications in the food industry, pharmaceuticals, and biotechnology. 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. NSF Award ID: 2542731 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Arnoldus Mathijssen | Institution: University of Pennsylvania, PHILADELPHIA, PA | Award Amount: $549,476 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2542731 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2542731.html