Osmoadaptation in Archaea

Abstract

The ability to adapt to fluctuations in external osmotic pressure (osmoadaptation) and the development of specific mechanisms to achieve this (osmoregulation) are fundamental to the survival of cells (6, 16, 67, 73, 76). Most cells maintain an osmotic pressure in the cytoplasm that is higher than that of the surrounding environment, resulting in an outward-directed pressure, turgor, whose maintenance is essential for cell division and growth. Changes in environmental osmolarity can trigger the flux of water across the cytoplasmic membrane. Thus, to avoid lysis under low-osmolarity or dehydration under high-osmolarity growth conditions, cells must possess active mechanisms that permit timely and efficient adaptation to changes in environmental osmolarity.