Extremophiles

Extremophiles represent heterogeneous biota from diverse habitats, such as subglacial Antarctic lakes, brine pools, and hydrothermal vents. Of the 15 categories of extremophiles, thermophiles, halophiles, psychrophiles, alkaliphiles, acidophiles, and piezophiles are identified and an overview of their physiological adaptations to exacting environmental conditions is presented. Their production of biocatalysts, or “extremozymes,” and extracellular polymeric substances (EPSs) as adaptation strategies to function under environmental stress is briefly pointed out. The production of several proprietary products and processes crucial for the discovery of novel bioactive compounds, genes, and gene products provides new opportunities for the biotechnological exploration of extremophiles. Only a few extremophiles are cultured at present, but in view of their potential biotechnological utility, we emphasize the need for more extensive culture studies.