Chemotactic response of bacteria to ephemeral nutrient gradients

Chemotaxis is the ability of bacteria to sense and react to different chemicals present in their environment. This enhances their ability to bias their motility towards favorable environments and colonize new regions or move away from toxic environments. Here, we study the chemotactic response of E coli to nutrient plumes emitting from hydrogels loaded with a chemoattractant in a microfluidic chip. We investigate how the interplay between flow and chemotaxis influences the bacterial distribution and migration around the hydrogels. We discuss the implications of our work for ecologically relevant phenomena such as bacterial colonization of marine snow.