School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Green Lane, Lincoln, LN6 7DL, UK.
Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
Sci Rep. 2017 May 17;7(1):2061. doi: 10.1038/s41598-017-01565-y.
The ability to rapidly detect and track nutrient gradients is key to the ecological success of motile bacteria in aquatic systems. Consequently, bacteria have evolved a number of chemotactic strategies that consist of sequences of straight runs and reorientations. Theoretically, both phases are affected by fluid drag and Brownian motion, which are themselves governed by cell geometry. Here, we experimentally explore the effect of cell length on control of swimming direction. We subjected Escherichia coli to an antibiotic to obtain motile cells of different lengths, and characterized their swimming patterns in a homogeneous medium. As cells elongated, angles between runs became smaller, forcing a change from a run-and-tumble to a run-and-stop/reverse pattern. Our results show that changes in the motility pattern of microorganisms can be induced by simple morphological variation, and raise the possibility that changes in swimming pattern may be triggered by both morphological plasticity and selection on morphology.
快速检测和跟踪营养梯度的能力是运动细菌在水生系统中生态成功的关键。因此，细菌已经进化出许多趋化策略，这些策略由一系列直线运动和重新定向组成。从理论上讲，这两个阶段都受到流体阻力和布朗运动的影响，而流体阻力和布朗运动本身又受到细胞几何形状的控制。在这里，我们通过实验探索了细胞长度对控制游动方向的影响。我们用抗生素处理大肠杆菌，得到了不同长度的游动细胞，并在均匀介质中对它们的游动模式进行了表征。随着细胞的延长，游动之间的角度变小，迫使游动模式从翻滚游动转变为游动-停止/反转模式。我们的结果表明，微生物游动模式的变化可以通过简单的形态变化来诱导，并且增加了游动模式变化可能是由形态可塑性和形态选择共同触发的可能性。
