Direct measurement of dynamic attractant gradients reveals breakdown of the Patlak-Keller-Segel chemotaxis model

• 成果类型: Article
• 署名作者: Phan, Trung V.; Mattingly, Henry H.; Vo, Lam; Marvin, Jonathan S.; Looger, Loren L.; Emonet, Thierry
• 署名单位: Yale University; Yale University; Simons Foundation; Flatiron Institute; Howard Hughes Medical Institute; University of California System; University of California San Diego; Howard Hughes Medical Institute; University of California System; University of California San Diego; Yale University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14719
• DOI: 10.1073/pnas.2309251121
• 发表日期: 2024-01-16
• 关键词: traveling bands; diffusion-coefficients; wound repair; amino-acids; bacteria; migration; motility; GROWTH; metabolism; biofilms

摘要

Chemotactic bacteria not only navigate chemical gradients, but also shape their environments by consuming and secreting attractants. Investigating how these processes influence the dynamics of bacterial populations has been challenging because of a lack of experimental methods for measuring spatial profiles of chemoattractants in real time. Here, we use a fluorescent sensor for aspartate to directly measure bacterially generated chemoattractant gradients during collective migration. Our measurements show that the standard Patlak-Keller-Segel model for collective chemotactic bacterial migration breaks down at high cell densities. To address this, we propose modifications to the model that consider the impact of cell density on bacterial chemotaxis and attractant consumption. With these changes, the model explains our experimental data across all cell densities, offering insight into chemotactic dynamics. Our findings highlight the significance of considering cell density effects on bacterial behavior, and the potential for fluorescent metabolite sensors to shed light on the complex emergent dynamics of bacterial communities.