Collective bacterial condensation is fundamentally constrained by the emergence of active turbulence
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Collective bacterial condensation arises from positive feedback between the ability of bacteria to generate chemical gradients and their chemotactic ability to track those gradients, resulting in the spontaneous formation of local cell accumulations. Here, by following the bacterial condensation dynamics in uniform acidic environments, we show that condensation is critically constrained by the spontaneous emergence of correlated bacterial swimming. Under the unique conditions prevailing within the condensate—characterized by sharp cell-density gradients and the absence of physical boundaries— correlated bacterial motion leads to vortex-like cell motion with an additional pronounced radial component directed down the cell-density gradient. This correlated motion induces active turbulence behavior associated with local fluid motion that broadens the condensate and expels non-chemotactic bacteria. However, when cells are embedded in a porous environment, correlated motion is suppressed, allowing spontaneous condensation to proceed further and form exceptionally dense bacterial accumulations. Overall, these findings highlight the fundamental interplay between self-generated bacterial condensation and correlated swimming.
Self-induced condensation and active turbulence are two prominent forms of collective bacterial behaviors. However, their interplay has not been experimentally studied. Here, we show that collective bacterial condensation gives rise to correlated swimming, which in turn fundamentally limits further condensation. Furthermore, we demonstrate that in dilute porous environments— common in natural bacterial habitats—correlated swimming is strongly suppressed, enabling the spontaneous formation of extremely dense cell condensates. These condensates may serve as a basis for the development of more structured bacterial communities.
