Hydrothermal vent ecosystems and representative hyperthermophilic microorganisms

One of the most spectacular events of the present century, concerning all biological and environmental disciplines, was the discovery of deep-sea hydrothermal vents around the Galapagos Islands, during the late 1970s. This remarkable scientific accomplishment was achieved thanks to the extensive work carried out by oceanographers and geologists. A significant role in terms of scientific support and technological development was played by the Woods Hole Oceanographic Institute (WHOI) and the Marine Biological Laboratory (MBL), both located at Woods Hole, MA (U.S.A.). These prestigious scientific institutions were able, almost two decades before the discovery of hydrothermal vents, to develop a manned submersible (ALVIN), able to reach great depths (3-4000 m) and collect many kinds of samples. Since then, this oceanographic vessel has been used extensively under the sea almost everywhere, but nowadays other submersibles are available and operated for outstanding projects also by french and japanese scientists. Hydrothermal vent ecosystems have been the target of several projects in different disciplines, as biology, chemistry, ecology, zoology, geology, microbiology; the peculiar microflora of these sites has been particularly investigated for taxonomical, evolutionary and biotechnological reasons. Moreover, hyperthermophilic microorganisms have been especially proposed for biotechnological applications mainly because their thermostable and hydrolytic enzymes. The taxonomy and physiology of representative species of deepsea bacteria and archaea are reported in this work; moreover, potential applications of these microorganisms as well as ocean drilling perspectives are discussed.