APPLICABILITY OF Pleurotus ostreatus AND Trametes versicolor FOR BIOREMEDIATION OF HEAVY METALS-POLLUTED SOILS

摘要

The presence of Cd decreased significantly the degradation of polycyclic aromatic hydrocarbons (PAH) during the growth of Pleurotus ostreatus in nonsterile soil. The same phenomenon was found in the case of decolorization of industrial dyes by several species of white-rot fungi. Toxic heavy metals interact with the lignin-degrading enzymes of fungi such as laccase, lignin peroxidase and Mn-peroxidase and modulate their activity both on the level of enzyme production and by in situ inactivation. In addition, the enzymes of energy metabolism of white-rot fungi (cellulase, hemicellulases) are also affected by the metals. The presence of heavy metals such as Cd or Hg leads to the decrease of the utilization rate of lignocellulose substrate, supplied as a source for the colonization of soil by fungal mycelia. Soil microflora co-operates with Pleurotus ostreatus and Trametes versicolor during PAH degradation. The main negative factor encountered in heavy-metals polluted soil is the reduction of growth and spread of fungal mycelia in the contaminated substrate, which is also accompanied by a reduction of the degradative potential of soil microflora.