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Information × Registration Number 0221U101227, 0119U101723 , R & D reports Title Dynamics of colloidal particles and bacteria in anisotropic medium. popup.stage_title Head Nazarenko Vasyl H., Registration Date 18-01-2021 Organization Department for special training National academy of science of Ukraine at Kiev University popup.description2  The coupling of the orientational nematic order and self-propelled bacteria movements results in a nontrivial direction of bacterial motion along linear paths which corresponds to the local anisotropy axis of the host. We report on an individual motion of bacteria in a lyotropic chromonic liquid crystal (LCLC). A resistive force for active bacteria is a main factor of determining their swimming condition. Indeed, microorganisms move in the realm of low Reynolds number Re << 1, because of a small length and a low swimming speed. This implies that inertial effects are negligible, the hydrodynamics is governed by the Stokes’ equation, and stresses felt by the swimmer are linear in the viscosity. Our experiments demonstrate that motility of separate bacteria in LCLC does not monotonically follow changes in an effective viscosity of surrounding. This conflicting dependence of the swimming velocity on the effective viscosity can’t be described exclusively from the balance of the viscous drag and propulsive force generated by bacteria flagella. The long-range orientational order of LC is expected to influence the velocity of an individual bacterium by inducing pairwise interactions between microswimmer and LC director distortions produced by bacterial flagella rotation. These findings show how behavior of active bacteria may be modified in anisotropic host and illustrate the potential of using complex fluids to manipulate microsized active particles. Product Description popup.authors Buluy Oleksandr H Selena Pavlina P. Skivka Larisa М. Tereshchenko Oleksandr G. Faidiuk Iuliia V. popup.nrat_date 2021-01-18 Close