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arXiv · 1407.6859

Filling an emulsion drop with motile bacteria

I. D. Vladescu·E. J. Marsden·J. Schwarz-Linek·V. A. Martinez·J. Arlt·A. N. Morozov·D. Marenduzzo·M. E. Cates·W. C. K. Poon
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Abstract

We have measured the spatial distribution of motile Escherichia coli inside spherical water droplets emulsified in oil. At low cell concentrations, the cell density peaks at the water-oil interface; at increasing concentration, the bulk of each droplet fills up uniformly while the surface peak remains. Simulations and theory show that the bulk density results from a `traffic' of cells leaving the surface layer, increasingly due to cell-cell scattering as the surface coverage rises above $\sim 10\%$. Our findings show similarities with the physics of a rarefied gas in a spherical cavity with attractive walls.

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I. D. Vladescu, E. J. Marsden, J. Schwarz-Linek, V. A. Martinez, J. Arlt, A. N. Morozov, D. Marenduzzo, M. E. Cates, W. C. K. Poon. 2014-07-25. Filling an emulsion drop with motile bacteria. https://doi.org/10.1103/physrevlett.113.268101

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