Extremophiles

The discovery of life in demanding environments continues to challenge conventional concepts of the growth-limiting conditions of many cellular organisms. Extremophiles may have diverse features; they may live at temperatures higher than 60 °C (thermophiles) or prefer colder sites, being able to grow between 5 °C and 20 °C; they may need pH <4 or >9 (acidophiles or alkaliphiles, respectively); or they can survive to high-salinity environments such as salty lakes (halophiles). They have been isolated in challenging biotopes from terrestrial solfataric fields to marine volcanic areas (Rothschild and Mancinelli 2001). The phylogenetic assessment of the isolated species widens between Archaea, Bacteria, and Eukarya. There has been a steady increase in the isolation of these microorganisms documenting the enormous scientific effort in the last 30 years. Although major advances have been made in the last decade, our knowledge of the physiology, metabolism, enzymology, and genetics of this...