TY  - JOUR
A1  - Theves, Matthias
A1  - Taktikos, Johannes
A1  - Zaburdaev, Vasily
A1  - Stark, Holger
A1  - Beta, Carsten
T1  - A bacterial swimmer with two alternating speeds of propagation
JF  - Biophysical journal
N2  - We recorded large data sets of swimming trajectories of the soil bacterium Pseudomonas putida. Like other prokaryotic swimmers, P. putida exhibits a motion pattern dominated by persistent runs that are interrupted by turning events. An in-depth analysis of their swimming trajectories revealed that the majority of the turning events is characterized by an angle of phi(1) = 180 degrees (reversals). To a lesser extent, turning angles of phi(2 Sigma Sigma Sigma Sigma) = 00 are also found. Remarkably, we observed that, upon a reversal, the swimming speed changes by a factor of two on average a prominent feature of the motion pattern that, to our knowledge, has not been reported before. A theoretical model, based on the experimental values for the average run time and the rotational diffusion, recovers the mean-square displacement of P. putida if the two distinct swimming speeds are taken into account. Compared to a swimmer that moves with a constant intermediate speed, the mean-square displacement is strongly enhanced. We furthermore observed a negative dip in the directional autocorrelation at intermediate times, a feature that is only recovered in an extended model, where the nonexponential shape of the run-time distribution is taken into account.
Y1  - 2013
U6  - https://doi.org/10.1016/j.bpj.2013.08.047
SN  - 0006-3495
SN  - 1542-0086
VL  - 105
IS  - 8
SP  - 1915
EP  - 1924
PB  - Cell Press
CY  - Cambridge
ER  -