During the last decades, high pressure has been an important physical parameter not only to study biomolecules, but also for its biotechnological applications. High pressure affects organism's ability to survive by altering most of cell's macromolecules. These effects can be used, for example, to inactivate microorganisms, enhance enzymatic reactions or to modulate cell activities. Moreover, some organisms are capable to growth under high pressures thanks to their adaptation at all cellular levels. Such adaptation confers a wide range of potentially interesting macromolecules still to be discovered. In this chapter, we firstly present the different effects of pressure on cells and the diverse strategies used to cope against this harsh environment. Secondly, we explored the pressure biotechnological applications on pressure-sensitive and adaptedpressure organisms.