Heavy metal uptake by Pleurotus sajor-caju from metal-enriched duckweed substrate

Abstract

The absorption of the heavy metals lead, cadmium, zinc, manganese, cobalt, copper, nickel and iron by duckweed, Lemna minor, and their translocation into the fruit bodies of the edible mushroom, Pleurotus sajor-caju, grown on metal-enriched duckweed have been investigated. A high concentration of heavy metals in the substrate reduced the biological efficiency of mushroom production. The translocation of heavy metals increased with an increase of these metals in the substrate. Among the heavy metals tested, zinc accumulated to the maximum extent in the fruit bodies. The more toxic metals, such as lead and cadmium, were translocated to a lesser extent in the mushrooms. However, the cadmium content of the mushroom was above the tolerable limit when harvested from substrates containing even 1–2 ppm of heavy metals.