In this special issue review articles summarize the most outstanding features of microorganisms that can survive under extreme conditions. These microorganisms are adapted to living at 100° C in volcanic springs, at low temperatures in the cold polar seas, at high pressure in the deep sea, at very low and high pH values (pH 0-1 or pH 10-11), or at very high salt concentrations (35%). The latest findings on the molecular biology and the protein structure of these exotic organisms are presented. In addition, the potential applications of extremophiles are reviewed, including the production of enzymes, compatible solutes and the use of these extremophiles in the degradation of xenobiotics.

Molecular adaptations in psychrophilic bacteria: Potential for biotechnological applications

Prokaryotes living under elevated hydrostatic pressure
Proteins from hyperthermophiles: Stability and enzymatic catalysis close to the boiling point of water
Molecular biology of hyperthermophilic Archaea
An overview of the role and diversity of compatible solutes in Bacteria and Archaea
Thermophilic degradation of environmental pollutants.