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

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 new 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.