Abstract
Escherichia coli is a predominantly non-pathogenic species of bacteria present in the gut of most healthy adults. It plays a critical role in the health of the gut microbiome and is also widely used as a model organism in microbiology and synthetic biology studies. This thesis discusses results from two ongoing projects on E. Coli organization and emergent biophysical properties at two very distinct length scales. The first project focuses on using genetically modified engineered E. coli bacteria for early detection and intervention in colorectal cancer (CRC), a significant public health issue in the US. The success of these engineered bacteria relies on their survival, engraftment, and proliferation. We constructed a mathematical model which combines the generalized Lotka-Volterra equations of population dynamics with diffusion and advection of individual bacteria to study the impact of different microbial interactions and motilities in the spatiotemporal and population dynamics of native and engineered bacterial populations. By examining the linear stability analyses and the time evolution of the coupled partial differential equations in our model, we aim to provide insights into engineered bacteria’s long-time survival, spatial distribution, and their colonization potential in combating CRC, to inform experiments by our collaborators. The second project delves into results on how stressed E. Coli use phase separation to organize their DNA, facilitated by DNA-binding proteins known as Dps, which are crucial for DNA compaction and protection under oxidative stress. We use an agent-based model and active Brownian dynamics simulations, which are informed by experiments, to obtain a quantitative biophysical understanding of Dps-DNA phase separation dynamics, extending beyond simple condensate formation to examine mechanical and structural properties of these complexes. This integrated approach aims to enhance our knowledge of protein-induced phase separation and can potentially guide the development of antibiotics targeting bacterial organization influenced by DPS proteins, opening new paths for therapeutic interventions.
Publication Date
8-2026
Document Type
Dissertation
Student Type
Graduate
Degree Name
Mathematical Modeling (Ph.D)
Department, Program, or Center
Mathematical Sciences, School of
College
College of Science
Advisor
Moumita Das
Advisor/Committee Member
Poornima Padmanabhan
Advisor/Committee Member
Elio Abbondanzieri
Recommended Citation
Alonso, Alberto, "Modeling Intercellular and Intracellular Organization and Dynamics Of the Bacteria Escherichia coli : From Population Dynamics in the Gut Microbiome, to Condensate Formation in Starved Cells" (2026). Thesis. Rochester Institute of Technology. Accessed from
https://repository.rit.edu/theses/12729
Campus
RIT – Main Campus

Comments
This thesis has been embargoed. The full-text will be available on or around 11/10/2027.