Collective motion in an active suspension of Escherichia coli bacteria

Autor: J Gachelin, A Rousselet, A Lindner, E Clement
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: New Journal of Physics, Vol 16, Iss 2, p 025003 (2014)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/16/2/025003
Popis: We investigate experimentally the emergence of collective motion in the bulk of an active suspension of Escherichia coli bacteria. When increasing the concentration from a dilute to a semi-dilute regime, we observe a continuous crossover from a dynamical cluster regime to a regime of ‘bio-turbulence’ convection patterns. We measure a length scale characterizing the collective motion as a function of the bacteria concentration. For bacteria fully supplied with oxygen, the increase of the correlation length is almost linear with concentration and at the largest concentrations tested, the correlation length could be as large as 24 bacterial body sizes (or 7–8 when including the flagella bundle). In contrast, under conditions of oxygen shortage the correlation length saturates at a value of around 7 body lengths.
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