BACTERIAL SENSITIVITY TO UV-LIGHT AS A MODEL FOR IONIZING-RADIATION RESISTANCE

Six bacterial isolates from the U.S. DOE Subsurface Science Program an d three reference bacteria were tested for resistance to UV light and gamma radiation. The subsurface isolates included three aerobic, pigme nted, Gram positive bacteria and three microaerophilic, non-pigmented, Gram negative bacteria. Deinococcus radiodurans was the most resistan t bacterium to both types of radiation, with a D37 value of 4.0 x 10(4 ) muWS CM-2 to UV light and 300 krads to gamma radiation. The aerobic subsurface bacteria were found to be significantly more resistant (p < 0.05) than the microaerophilic subsurface bacteria to UV light and ga mma radiation. Due to the similarities of bacterial survival between U V and gamma radiation; it is proposed that UV light could be utilized to model the fate of microorganisms exposed to ionizing radiation.