Visualizing self-generated gradients of chemoattractants by bacteria

Chemotactic bacteria such as E. coli can bias their motility in response to local concentrations of chemicals, which are also influenced by the bacteria themselves. Here, we repurpose a fluorescent sensor for the attractant aspartate, developed in the neuroscience community, to visualize self-generated gradients during collective bacterial migration. Our preliminary results are consistent with a Patlak-Keller-Segel-type model of collective migration. However, they also suggest that the presence of multiple attractants, like oxygen, can generate complex, geometry-dependent spatial arrangements of chemotaxis phenotypes.