World ocean covers about 70% of the earth's surface, with about 3,800m of the average depth and more than 11,000m of the deepest trench areas. Deep-sea area is characterized by low temperature, high hydrostatic pressure, low concentration of organic matter (available nutrients) and complete darkness, which restrict existence of most terrestrial and marine surface microorganisms. However, there have been finding and isolation of living microorganisms, which are called as barophile(pressure-loving microorganisms) and have probably adapted to such extreme environmental conditions with long duration of time. In this paper, characteristic nature of barophilic microorganisms so far studied has been reviewed.
