Collaborative Research: Spatiotemporal Dynamics of Interacting Bacterial Communities in Compact Colonies

细菌是地球上最简单、最丰富的生命体，通常以复杂的微生物群落形式存在于同质环境中。该项目提出解决细菌群落如何生存、扩大和保持其多样性的问题。该项目的主要目标是：(1)揭示在不断生长的细菌群体内产生和维持复杂的生化和机械环境的规则，这些环境是繁殖遗传和生态多样性的源泉；以及(2)产生一套经过充分测试的数学模型和计算工具，用于研究个体细胞的活动和群落一级的集体细菌行为之间的相互作用。PIS将参与一系列旨在培养在数学和生物科学交叉领域接受培训的下一代劳动力的活动，包括在加州大学圣迭戈分校开设一个新的本科数学生物学专业，在加州大学圣迭戈分校和巴克内尔大学开设数学生物学课程，以及在所有三个合作机构培训这一跨学科领域的本科生和研究生。加州州立大学长滩分校还将举办一系列关于数学生物学的公开讲座，这是一所拥有43%拉美裔/拉丁裔学生的大型公立大学。该项目将结合实验和多尺度建模来研究空气-琼脂界面上生长的致密细菌菌落的时空动力学。非细胞外基质产生菌将作为一种简化的实验系统来研究细菌生长过程中机械性能和代谢的相互关系。多个细菌物种之间的交叉饲养将被用来探索细菌多样性对菌落生长的影响。在这个项目中，将开发一个离散-连续的3D模拟模型，该模型将能够集成机械和代谢相互作用及其对单个细胞的耦合处理，并与环境因素的连续描述相结合。这个项目的结果应该会阐明管理细菌生长和多样性的规则。此外，拟议的研究在新的数学研究中提供了许多机会和挑战，主题包括非线性偏微分方程、界面动力学、多尺度建模和高性能科学计算。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.