Molecular Adaptation to Radiation and Bioremediation Prospects in Deinococcus radiodurans

The expression “radiation-eating bacteria” is frequently used in popular science to describe microorganisms that survive, interact with, or potentially benefit from high-radiation environments. Scientifically, however, the phrase is imprecise. The best-characterized bacterial example is Deinococcus radiodurans, an exceptionally radioresistant microorganism capable of surviving radiation doses far beyond those tolerated by most bacteria. Its extraordinary phenotype is not explained by consumption of ionizing radiation as a conventional metabolic substrate. Instead, survival arises from a coordinated system involving genome organization, protection of proteins from oxidative damage, manganese-associated antioxidant chemistry, stress-response regulation, and highly efficient DNA repair. Recent work has further identified specialized DNA-break recognition machinery, including DdrC that helps stabilize damaged DNA and facilitate repair. This review examines the distinction between radiation resistance and true radiotrophy, summarizes the cellular and molecular mechanisms that permit D. radiodurans to recover from severe irradiation, and evaluates its potential for environmental biotechnology. Particular attention is given to uranium biosorption and bioprecipitation, where engineered D. radiodurans strains have demonstrated substantial radionuclide-removal capacity. The evidence indicates that the most defensible scientific description is “extremely radiation-resistant bacterium,” while claims that the organism literally feeds on radiation require substantially stronger metabolic evidence. The field nevertheless provides an important platform for understanding stress biology, DNA repair, synthetic biology, and the treatment of radionuclide-contaminated environments.

Keywords: Deinococcus radiodurans; ionizing radiation; radiation resistance; DNA repair; oxidative stress; manganese; DdrC; uranium bioremediation; radionuclides; extremophiles.