Microbiological Status of Peat Soil in the Exclusion Zone of the Chernobyl Nuclear Power Plant

The work examines the number of the main physiological groups of microorganisms in the peat soil of the exclusion zone of the Chernobyl nuclear power plant. Methods: Koch cup method, agrochemical methods, γ-spectrometry, statistical analysis. An analysis of the numbers of the main physiological groups of microorganisms showed that a peat soil sample II, which was characterized by a lower level of contamination with technogenic radionuclides as compared to sample I, contains a smaller amount of ammonifying and phosphate — mobilizing bacteria, as well as micromycetes, respectively, more than 2–20 times compared with sample I. For the remaining studied groups of microorganisms in sample II, in comparison with sample I was noted an excess of the number of microorganisms by less than 1.5 times. For this soil sample, the largest number is typical for autochthonous microorganisms, then in a row with decreasing numbers are presented: amylolytic, oligonitrophilic, spore ammonifiers, cellulose–destroying aerobic bacteria. It was established that the peat soil of sample plot I is characterized by a greater degree of enrichment of the soil with microorganisms. This is due, firstly, with an increased water content in the peat sample I (up to 90%) that promotes rapid growth soil microorganism’s population; secondly, it is determined by a large number of plant roots. The density of peat soil radionuclide contamination to a lesser extent affects the quantitative content of most of the physiological groups of microorganisms studied in it