Forces and torques on rotating spirochete flagella.
Forces and torques on rotating spirochete flagella.
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DOI：
10.1103/physrevlett.107.268101
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发表时间：
2011-12-23
影响因子：
8.6
通讯作者：
Wolgemuth CW
中科院分区：
文献类型：
--
作者：
Yang J;Huber G;Wolgemuth CW
螺旋体是一种独特的活动细菌，其特点是螺旋或平波形状和鞭毛的位置，鞭毛位于细菌细胞壁和外膜（外质）之间的微小空间内。在伯氏疏螺旋体中，鞭毛的旋转产生驱动游泳的细胞波动。由于鞭毛和细胞体之间的力和扭矩作用，这些形状变化是如何产生的尚不清楚。阻力可能来自摩擦或流体阻力，这取决于鞭毛是否与细胞壁接触。这里，我们考虑这两种情况。通过分析弹性鞭毛在质周空间中旋转的运动，我们表明鞭毛很可能是由一层润滑流体与细菌细胞壁分离的。这种分析提供了鞭毛在外周质内旋转和滑动的阻力系数。
Spirochetes are a unique group of motile bacteria that are distinguished by their helical or flat-wave shapes and the location of their flagella, which reside within the tiny space between the bacterial cell wall and the outer membrane (the periplasm). In Borrelia burgdorferi, rotation of the flagella produces cellular undulations that drive swimming. How these shape changes arise due to the forces and torques that act between the flagella and the cell body is unknown. It is possible that resistive forces come from friction or from fluid drag, depending on whether or not the flagella are in contact with the cell wall. Here, we consider both of these cases. By analyzing the motion of an elastic flagellum rotating in the periplasmic space, we show that the flagella are most likely separated from the bacterial cell wall by a lubricating layer of fluid. This analysis then provides drag coefficients for rotation and sliding of a flagellum within the periplasm.