Deep Ocean Microbiological Studies. Part I. Physiological Interaction of Hydrostatic and Osmotic Pressure

High hydrostatic compression exerts depressive physiological effects on various microorganisms, including protozoans. In this report, experiment results are presented which show that some effects of high hydrostatic pressure are negated by increased osmotic pressure of the media (with salt or sucrose). In water with a salinity of 35 parts per thousand or osmotically equivalent sucrose concentration, the effects of 525 kilograms per centimeter square pressure (equivalent to an ocean depth of about 17,000 feet) were diminished. Explanations for this phenomenon are discussed in relation to this new finding of osmotic protection.