Investigation of the effect of radiation on antioxidant system of Escherichia coli and Radiation resistant Deinococcus radiodurans

It is difficult to determine the limits of the vitality because the living creatures exhibit a great deal of variations. There are organisms living in the very depth of ocean, under the earth, in the dark, pressurized media, in high or low temperatures and in high radiation environment. In last 30-35 years, it has been discovered that many organisms can live in environments considered as extreme for mankind. Since these microorganisms can live in the extreme environments, they are named as extremophiles. One of the recently-discovered microorganisms, Deinococcus radiodurans, had drawn attention for its extraordinary capabilities and its potential of infinity. D. radiodurans is resistant that genotoxic chemicals, oxidative damage, high-level ionization, ultraviolet radiation and dehidration. Because of these features is also name as polyextremophile. In recent years, studies on bioremediation and related to heavy metal and detoxification of xenobiotics which cause serious environment problems, as well as genetic engineering, have been intense. However, the reactive oxygen species, induces of UV and their effects, their cellular defense mechanisms against ROS and about antioxidative systems responsible for cleaning of reactive oxygen species enough research has not been made.To this end; in Ecsherichia coli and radiation-resistant D. radiodurans bacteria were compared and tested effects on levels GSH and antioxidant system of radiation. In both bacteria, enzyme activity and GSH levels has been determined after the different doses of ? radiation applications. In the end of our study, high activities in enzyme especially superoxide dismutase and catalase of D. radiodurans were observed depending on the different doses ? radiation applications. Moreover, it was determined that enzyme and GSH levels were decreased in E. coli depending on the radiation levels.