The effect of multiple ionizing radiation on the activity of antioxidant enzymes of Escherichia coli ”PL-6” cells

The article presents the analysis of enzymatic activity of Escherichia coli “PL-6” cells following multiple gamma irradiation with increasing doses. For irradiation the stationary gamma ray unit “Researcher” (60Co) with the dose rate of 36.7 Gy/min was used. Radiation doses to the bacterial cells increased from 3.5 to 10 kGy in 0.5 kGy increment, and from 10 to 30 kGy in 5 kGy increment. Unirradiated suspended bacterial cells were used as control. The irradiated cells enzymatic activity was estimated with the spectrophotometric method on the "MultiSkan Go" device (Thermo Fisher Scientific, Finland). The results of the study demonstrate the increase in the E. coli ”PL-6” cells radioresistance caused by gamma irradiation of the cells with gradually increased doses. Exposure of the bacteria to a higher gamma radiation dose caused decrease in the number of viable cells from 109 CFU/ml in the control culture sample to 102 CFU/ml after irradiation at a dose of 30 kGy. The most radiation-resistant cells were selected from cells undergone successive multiple irradiation with constantly increasing dose of ionizing radiation. The enzymes of the antioxidant system in irradiated cells exhibit increased specific activity as compared to the enzymes in control, unirradiated, cells. The activity of enzymes increases with an increase in the radiation dose. Catalase activity increased after multiple irradiation by 5 times and peroxidase activity increased by 4 times. To compare the results in the groups, the Student's t-test was applied at p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }