ABSTRACT
This study showed the effect of Pleurotus ostreatus on the external organic matter (OM) transformation processes. The kinetics of these changes were determined. The experiment was conducted as 42-day pot experiment done in four combinations (with four replications). The four combinations of different substrates were: (1) organic, (2) composted hay, (3) organic soil + composted hay, (4) organic soil + composted hay + lead. The study results showed that P. ostreatus had the ability to transform external OM as well as metal-organic complexes. These transformations were reflected in the constant rate of characterized changes and correlation coefficients. The study also indicated the direction of the external OM transformation. The direction leads to the selective oxidation of aliphatic structures, and an increase in humic substances which are resistant to oxidation. The study also identified the negative impact of lead on the ability of P. ostreatus to transform humic substances. The impact of lead was expressed as the lower value of the rapid rate constant k1 in objects enriched with lead acetate.
