| Abstract: | The microbial activity of pristine and contaminated soils was investigated by measuring the following parameters: glucose induced respiration, dimethylsulphoxide reduction and the hydrolysis of fluorescein diacetate. The viable counts were determined by the plate count method. The ability of the autochthonous microorganisms of the investigated soils to degrade diesel fuel was determined in a closed system on the basis of the oxygen consumption and by direct measurements of the hydrocarbon concentrations. As expected, compost showed the highest microbial activity with regard to all three parameters, followed by the grassland and the arable soil samples which were also found to have high activity. However, soils that had been exposed to mineral oil for a long period of time showed significantly lower values. Microorganisms from contaminated sites had a high degradation potential; few pristine soils reached similar turnover rates. The investigations showed that the level of the degradation of diesel fuel in pristine soils correlated with their microbial activity, but this correlation was not found in the investigated contaminated soils. |
