The pressure relationships of halophilic and non-halophilic prokaryotic cells determined by using gas vesicles as pressure probes

Abstract

Gas vesicles can be used to measure the hydrostatic pressure (turgor pressure) in prokaryotic cells. Halophilic cyanobacteria have turgor pressures that are substantially less than those of cyanobacteria from fresh water. Turgor pressure acts so as to tend to burst cell walls and collapse hollow gas vesicles. The halophiles take advantage of their lower turgor pressures by producing cell walls that are relatively thinner and gas vesicles that are relatively wider than in the mesophilic cyanobacteria. In this way the halophilic structure encounters the same stress and saves on material. Extreme halophiles, with negligible turgor, have been able to adopt various shapes and to produce the weakest and widest gas vesicles.