Related papers: Density-Dependent Transition in Bacterial Self-Org…
This fluid dynamics video presents three-dimensional kinetic simulations of the dynamics in suspensions of oxytactic bacteria confined in thin liquid film surrounded by air. At the initial time, the bacterial concentration is uniform and…
We model an enclosed system of bacteria, whose motility-induced phase separation is coupled to slow population dynamics. Without noise, the system shows both static phase separation and a limit cycle, in which a rising global population…
Aerotaxis is the ability of motile cells to navigate toward oxygen. A key question is the dependence of the aerotactic velocity with the local oxygen concentration c. Here we combine simultaneous bacteria tracking and local oxygen…
Navigation of microorganisms is controlled by internal processes ultimately sensitive to mechanical or chemical signaling encountered along the path. In many natural environments, such as porous soils or physiological ducts, motile species…
Bacterial colonies are a well-known example of living active matter, exhibiting collective behaviors such as nematic alignment and collective motion that play an important role in the spread of microbial infections. While the underlying…
A variety of bacterial species spontaneously assemble in aerotactic band, local accumulation at a fixed distance from the air-water interface. Although the phenomenon is long known, its modelling is so far limited to mesoscopic,…
In this fluid dynamics video we explore the nature and causes of the spontaneous ordering that emerges in a dense bacterial suspension under confinement. Recent experiments with B. Subtilis confined within small flattened drops show that…
Bacterial colonies growing on surfaces are shaped by mechanical stresses transmitted through the community, governed by the balance between cell growth and steric and cell-substrate interactions. Using overdamped dynamics simulations of…
Confining surfaces play crucial roles in dynamics, transport and order in many physical systems, but their effects on active matter, a broad class of dynamically self-organizing systems, are poorly understood. We investigate here the…
Colonies of bacteria grown on thin agar plate exhibit fractal patterns as a result of adaptation to their environments. The bacterial colony pattern formation is regulated crucially by chemotaxis, the movement of cells along a chemical…
The large-scale collective behavior of biological systems can be characterized by macroscopic transport, which arises from the non-equilibrium microscopic interactions among individual constituents. A prominent example is the formation of…
The evolutionary success of bacteria lies in their ability to form complex surface-associated communities in diverse biophysical settings. However, it remains poorly understood how compliance of soft surfaces, measured in terms of their…
Dense suspensions of swimming bacteria are known to exhibit collective behaviour arising from the interplay of steric and hydrodynamic interactions. Unconfined suspensions exhibit transient, recurring vortices and jets, whereas those…
During colony growth, complex interactions regulate the bacterial orientation, leading to the formation of large-scale ordered structures, including topological defects and microdomains. These structures may benefit bacterial strains,…
We investigate the emergence of global alignment in colonies of dividing rod-shaped cells under confinement. Using molecular dynamics simulations and continuous modeling, we demonstrate that geometrical anisotropies in the confining…
A simulation approach to the stochastic growth of bacterial towers is presented, in which a non-uniform and finite nutrient supply essentially determines the emerging structure through elementary chemotaxis. The method is based on cellular…
Motile bacteria can migrate along chemical gradients in a process known as chemotaxis. When exposed to uniform environmental stress, Escherichia coli cells coordinate their chemotactic responses to form millimeter-sized condensates…
The self-organization of microbial ecosystems involves a large variety of mechanisms, ranging from biochemical signaling to population dynamics. Among these, the role of motility regulation has been little studied, despite the importance of…
We numerically study the dynamics of run-and-tumble particles confined in two chambers connected by thin channels. Two dominant dynamical behaviors emerge: (i) an oscillatory pumping state, in which particles periodically fill the two…
The field of active matter explores the behaviors of self propelled agents out of equilibrium, with active suspensions, such as swimming bacteria in solutions, serving as impactful models. These systems exhibit spatio-temporal patterns akin…