gas vacuole

A gas vacuole is a membrane-bound compartment within a cell that contains gas. These structures are found in some prokaryotic organisms, such as certain bacteria and archaea. Gas vacuoles are not found in eukaryotic cells.1

The primary function of gas vacuoles is to provide buoyancy to the cell, allowing it to regulate its position in the water column. This is particularly important for aquatic microorganisms that need to access sunlight for photosynthesis or find optimal conditions for growth. The gas vacuole is composed of protein subunits that form a hydrophobic barrier, preventing water from entering while allowing gases to diffuse in and out, thus enabling the cell to control its buoyancy.1