Others, seemingly suited to life at one atmosphere, function well when exposed to a range of pressures. This adaptability raises questions about how microorganisms adjust to pressure and what these adaptions may say about their evolution. But, so far, pressure as an environmental factor for microorganisms has not been studied extensively. Adaptations for high pressure in microorganisms are called barotolerance. Understanding how these barophiles work might improve the understanding of pressure's impact on protein structure and DNA replication.
Scientists know little of the biochemistry, molecular biology, and genetics of pressure adaptation.
Laboratory studies of about two dozen ocean-dwelling microorganisms from a variety of depths suggest that many experience optimal growth in the laboratory at pressures at or above the pressure at which they were collected. Others caution, however, that some of these findings may be a result of culture conditions. In the laboratory, for instance, the microorganisms receive large amounts of high-quality nutrients and endure no competition. To know with certainty whether organisms in their native habitat require pressure to survive, laboratory parameters must more closely parallel environmental conditions. Finding organisms that do well under both high temperature and pressure could alter theories about the evolution of microorganisms.