Bacteria are the simplest and most abundant living organisms on our planet, and often exist as complex microbial communities in otherwise homogeneous environment. This project proposes to address the question of how bacterial communities survive, expand, and maintain their diversity. The main goals of this project are to: (1) uncover rules that generate and maintain the complex biochemical and mechanical environment inside growing bacterial colonies, which serve as the fountain that breeds both genetic and ecological diversity; and (2) produce a set of well-tested mathematical models and computational tools for investigating the interplay between activities of individual cells and the collective bacterial behaviors at the community level. The PIs will engage in a number of activities aimed at development of the next generation workforce trained at the intersection of mathematical and biological sciences including the development of a new undergraduate major in mathematical biology at UCSD, development of courses in mathematical biology at UCSD and Bucknell and the training of undergraduate and graduate students in this interdisciplinary area at all 3 collaborating institutions. A series of public lectures on mathematical biology will also be arranged in California State University - Long Beach, a large public university with 43% Hispanic/Latino students.
This project will use a combination of experimentation and multiscale modeling to address the spatiotemporal dynamics of growing compact bacterial colonies on the air-agar interface. Non-extracellular matrix producing bacteria will be used as a simplified experimental system to address the interrelationship of mechanical properties and metabolism on bacterial grown. Cross feeding between multiple bacterial species will be used to explore the impact of bacterial diversity on colony growth. A discrete-continuum 3D simulation model will be developed in this project that will be able to integrate mechanical and metabolic interactions as well as its couple treatment of individual cells and with a continuum description of environmental factors. The results of this project should shed light on the rules that govern bacterial grown and diversity. In addition, the proposed research provides many opportunities and challenges in new mathematical studies on topics ranging from nonlinear partial differential equations, interface dynamics, multiscale modeling, and high performance scientific computing.
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.
