ABSTRACT
The substrate mixtures were created in the study, using spent coffee grounds for Pleurotus ostreatus cultivation with the addition of straw and fluidized bed ash at 5 and 10 percent by weight relative to the total weight of coffee grounds. In order to determine the ability to accumulate heavy metals and the possibility of further waste management, analyses of micro- and macronutrients, biogenic elements, as well as the metal content of fungal fruiting bodies, mycelium and post-cultivation substrate were performed. The addition of 5 percent resulted in slower growth of mycelium and fruiting bodies, and with the addition of 10 percent, the growth of fruiting bodies was completely inhibited. The accumulation of elements such as (Cr), (Cu), (Ni), (Pb) and (Zn) was reduced in the fruiting bodies grown on the substrate with the addition of 5 percent fly ash, compared to spent coffee grounds without additives.