The Motility of Bacteria in an Anisotropic Liquid Environment

Although the influence on bacterial motility of many genetic and biochemical factors has been extensively studied, there have been limited studies of the impact of physical parameters. Indeed, despite the fact that natural environments are often asymmetric (such as stretched supramolecular structures), the majority of behavioral experiments with bacteria have been done in isotropic liquid solutions. In the present work, we show that the behavior of living microorganisms is dramatically different in media that are asymmetric. The example of Escherichia coli bacteria swimming in a bulk uniaxial liquid environment is used to demonstrate this phenomenon. The results of our study provide insight into the behavior of bacteria in conditions encountered in real environments and open new avenues for the control of their movements.