Quantitative Biosciences Thesis Proposal
Ray Copeland
School of Physics
Advisor: Dr. Peter Yunker (School of Physics)
Open to the Community
Physical Simulations of Microbial Population Dynamics
Friday, September 27, 2024
11:00am
In Person Location: Cherry Emerson, Room 204
Zoom Link: https://gatech.zoom.us/j/7615576281?omn=93425677064
Committee Members:
Dr. William Ratcliff (School of Biological Sciences)
Dr. JC Gumbart (School of Physics)
Dr. Brian Hammer (School of Biological Sciences)
Abstract:
Bacterial communities play a crucial role in human health, ranging from pathogenic organisms that cause diseases to the gut microbiome that influences digestion and overall well-being. These microbial populations face various lethal pressures, including interspecies warfare and antibiotic exposure, which significantly shape their composition.
Microbial warfare can rapidly alter population dynamics, potentially eradicating entire genotypes within a few generations. The type VI secretion system has recently garnered significant attention as a mechanism for such warfare. However, literature reveals a diverse array of toxins with varying lethality rates. In our paper, "Spatial constraints and stochastic seeding subvert microbial arms race," we employ various physical simulation assumptions to demonstrate that spatial limitations and random seeding patterns diminish the effectiveness of contact-dependent killing processes. These findings suggest that realistic environmental conditions play a crucial role in shaping bacterial community composition.
In another study, I investigate how beta-lactamase enzyme efficiency influence population dynamics under antibiotic pressure. Using a mean-field model incorporating multiple bacterial strains, enzyme production, and antibiotic degradation, we reveal counterintuitive dynamics in antibiotic resistance evolution. Our findings demonstrate that increased enzyme efficacy doesn't always benefit resistant populations at the community level, and that diverse bacterial communities cannot always, but sometimes can, be accurately represented by average behaviors.
My future work will focus on how the antibiotic resistance dynamics above are altered in spatially structured settings, and how diffusive warfare impacts the spatial structure of microbial communities.