The cytoplasm of bacterial cells is a highly crowded cellular compartment that possesses considerable osmotic potential. As a result, and owing to the semipermeable nature of the cytoplasmic membrane and the semielastic properties of the cell wall, osmotically driven water influx will generate turgor, a hydrostatic pressure considered critical for growth and viability. Both increases and decreases in the external osmolarity inevitably trigger water fluxes across the cytoplasmic membrane, thus impinging on the degree of cellular hydration, molecular crowding, magnitude of turgor, and cellular integrity. Here, we assess mechanisms that permit the perception of osmotic stress by bacterial cells and provide an overview of the systems that allow them to genetically and physiologically cope with this ubiquitous environmental cue. We highlight recent developments implicating the secondary messenger c-di-AMP in cellular adjustment to osmotic stress and the role of osmotic forces in the life of bacteria-assembled in biofilms.

中文翻译：

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微生物对渗透胁迫的反应。

细菌细胞的细胞质是高度拥挤的细胞区室，具有相当大的渗透潜力。结果，由于细胞质膜的半透性和细胞壁的半弹性，渗透压驱动的水涌入会产生膨胀力，这对于生长和生存力至关重要。外部渗透压的增加和减少都不可避免地触发了水通过细胞质膜的通量，从而影响了细胞的水合作用程度，分子拥挤，膨胀程度和细胞完整性。在这里，我们评估了允许细菌细胞感知渗透压的机制，并提供了使它们能够通过遗传和生理学应对这种普遍存在的环境提示的系统的概述。