COULD THE MUSHROOM PLEUROTUS BE USED TO MAINTAIN CLEAN ENVIRONMENT?

White-rot fungi are known to degrade natural macromolecules such as lignin, humic substances as well as toxic anthropogenic pollutants via non-specific oxidative enzymatic systems. Pleurotus ostreatus, is a common and commercially important edible fungus. The ligninolytic system of P. ostreatus has been found to be mainly composed of the lignin-modifying enzymes laccase and two types of peroxidases: Mn²⁺-dependent peroxidase and versatile peroxidase (VP). These enzymes can function separately and/or in cooperation. The exceptional oxidative potential and lack of specific substrates allow the degradation of a long list of environmental contaminants in addition to the natural substrate, lignin. The ligninolytic system of P. ostreatus was studied with emphasis on the biochemistry of VP and its production under various growth and reaction conditions and its role in decolorization of textile dyes. We also investigated mechanisms by the ligninolytic system participates in the metabolism of the pharmaceutical compound carbamazepine, which is extremely stable in the environment. When P. ostreatus was grown on cotton stalks, 90% of the added CBZ was removed. Formation of 25 transformation products during growth on cotton stalks was observed in comparison only two transformation products on glucose peptone medium. Since many environmental aromatic pollutants exhibit chemical structure which is similar to that of lignin subunits, it is suggested that the fungus may be used for bioremediation processes.