ABSTRACT
This chapter deals with the mechanisms governing radiation-resistant in thermophiles and their potential biotechnological applications ranging from exploitation of engineered strains for treatment of radionuclides contaminated environments to astrobiology. The existence of microbial life in inhospitable environments, viz., geothermal regions, hydrothermal vents, acidic, and hot geysers have unveiled the presence of special category of microorganisms known as thermophiles or hyperthermophiles. Thermophiles are the center of curiosity amongst the scientific community from the viewpoint of the mechanisms, which provide the ability to cope up simultaneously with variety of stresses, viz., desiccation, radiation, and pressure along with elevated temperature. Radiation resistant thermophiles possess genes for detoxification and removal of toxic elements, which extends their application in the field of metal bioremediation also. The surviving conditions of early Earth resemble that of the present-day habitat of thermophiles, which supports the hypothesis that thermophiles were the first life forms on Earth.
