Abstract
Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on active turbulence in highly concentrated 3D suspensions of Bacillus subtilis and compare them with a minimal fourth-order vector-field theory for incompressible bacterial dynamics. Velocimetry of bacteria and surrounding fluid, determined by imaging cells and tracking colloidal tracers, yields consistent results for velocity statistics and correlations over 2 orders of magnitude in kinetic energy, revealing a decrease of fluid memory with increasing swimming activity and linear scaling between kinetic energy and enstrophy. The best-fit model allows for quantitative agreement with experimental data.
- Received 21 February 2013
DOI:https://doi.org/10.1103/PhysRevLett.110.228102
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Published by the American Physical Society
Viewpoint
ViewpointThe Aquatic Dance of Bacteria
Published 28 May 2013
Researchers apply a new experimental approach to visualize the turbulent motion of swimming bacteria and propose a minimal model that captures their observations.
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