Impact Assessment of Soil Contamination with Antibiotics (for Example, an Ordinary Chernozem)

The environmental behavior of antibiotics is not well known and the precise environmental risk assessment is not practical. We studied the impact antibiotics (benzylpenicillin, pharmasin and nystatin) at different concentrations (100 and 600 mg kg^-1) on population densities of microorganisms and enzymatic activity of ordinary chernozems in model experiments. The applied doses of antibiotics had definite suppressing effects on population densities of microorganisms (up to 30-70% of the control) and on the soil enzymatic activity (20-70% of the control). The correlation analysis of the obtained data revealed positive correlation of enzymes of two studied classes (dehydrogenase, invertase) with a number of micromycetes (r = 0.63, r = 0.65, respectively), catalases with ammonifying bacteria (r = 0.73) and the return correlation of phosphatase with amylolytic bacteria (r = -0.80). The effect of antibiotics on the biological properties of the chernozem lasted for a long time. The studied parameters were not completely recovered in 120 days.