Responses of Ganoderma lucidum to heavy metals

Abstract

The levels of seven heavy metals and their toxicity toward Ganoderma lucidum under various cultivation conditions were assessed. The contents of Mn, Cu, Zn, Cd, Hg, Pb and U in the fruitbodies of cultivated G. lucidum and sawdust substrates were determined to be at trace levels for U, 0.01–0.1 μg/g for Cd and Hg, and 1–5 μg/g for Pb, 10–120 μg/g for Mn, Cu and Zn. The effects of heavy metals on the growth of mycelia of G. lucidum in pure cultures were examined over a wide range of concentrations (l0–3,000 μg/ml), and their toxicities were found to decrease in the order: Hg>Cd>Cu>U>Pb>Mn=Zn. The translocation and accumulation of Zn from contaminated substrates (at 10 μg/g) in fruitbodies were investigated by using 65Zn tracer, and G. lucidum was found to take up Zn with an efficiency of >60%, leading to accumulation of > 100 μg/g in fruitbodies and >80 μg/g Zn in basidiospores.