Bacteria have developed a large array of motility mechanisms to exploit available resources and environments. These mechanisms can be broadly classified into swimming in aqueous media and movement over solid surfaces. Swimming motility involves either the rotation of rigid helical filaments through the external medium or gyration of the cell body in response to the rotation of internal filaments. On surfaces, bacteria swarm collectively in a thin layer of fluid powered by the rotation of rigid helical filaments, they twitch by assembling and disassembling type IV pili, they glide by driving adhesins along tracks fixed to the cell surface and, finally, non-motile cells slide over surfaces in response to outward forces due to colony growth. Recent technological advances, especially in cryo-electron microscopy, have greatly improved our knowledge of the molecular machinery that powers the various forms of bacterial motility. In this Review, we describe the current understanding of the physical and molecular mechanisms that allow bacteria to move around.

细菌已经开发出大量的运动机制来利用可用的资源和环境。这些机制可以大致分为在水性介质中游泳和在固体表面上运动。游泳运动涉及刚性螺旋细丝通过外部介质的旋转或响应于内部细丝旋转的细胞体的旋转。在表面上，细菌聚集在一层薄薄的流体中，由刚性螺旋丝的旋转提供动力，它们通过组装和拆卸 IV 型菌毛来抽动，它们通过驱动粘附素沿着固定在细胞表面的轨道滑动，最后是非运动的由于菌落生长，细胞会在外向力的作用下滑过表面。最近的技术进步，特别是在低温电子显微镜方面，极大地提高了我们对为各种形式的细菌运动提供动力的分子机制的认识。在这篇综述中，我们描述了目前对允许细菌四处移动的物理和分子机制的理解。