Radiation resistance in thermophiles: mechanisms and applications

Abstract

The study of prokaryotic life in high temperature environments viz., geothermal areas, hot, acidic geysers and undersea hydrothermal vents has revealed the existence of thermophiles (or hyperthermophiles). These microorganisms possess various stress adaptation mechanisms which enable them to bypass multiple physical and chemical barriers for survival. The discovery of radiation resistant thermophile Deinococcus geothermalis has given new insights into the field of radiation microbiology. The ability of radiation resistant thermophiles to deal with the lethal effects of ionizing radiations like DNA damage, oxidative bursts and protein damage has made them a model system for exobiology and interplanetary transmission of life. They might be an antiquity of historical transport process that brought microbial life on Earth. These radiation resistant thermophiles are resistant to desiccation as well and maintain their homeostasis by advance DNA repair mechanisms, reactive oxygen species (ROS) detoxification system and accumulation of compatible solutes. Moreover, engineered radioresistant thermophilic strains are the best candidate for bioremediation of radionuclide waste while the extremolytes produced by these organisms may have predicted therapeutic uses. So, the present article delineate a picture of radiation resistance thermophiles, their adaptive mechanisms to evade stress viz., radiation and desiccation, their present applications along with new horizons in near future.

Keywords: Deinococcus; Extremolytes; Ionizing radiations; Reactive oxygen species (ROS); Thermophiles.