Silver uptake by Agaricus bisporus from an artificially enriched substrate

Area of Science:

• Agricultural Science
• Environmental Science
• Mycology

Background:

• Silver (Ag) is a heavy metal with potential applications in agriculture.
• Understanding metal accumulation in edible fungi like Agaricus bisporus is crucial for food safety.
• Mushroom cultivation relies on nutrient-rich compost, which can be a pathway for contaminant uptake.

Purpose of the Study:

• To investigate the accumulation of silver in Agaricus bisporus grown on silver-fortified compost.
• To determine the relationship between silver concentration in the substrate and its uptake by mushrooms.
• To assess potential toxicity of silver on mushroom growth and development.

Main Methods:

• Cultivation of Agaricus bisporus on compost artificially fortified with silver nitrate at varying concentrations (0.01–10.3 mg/kg).
• Quantification of silver content in mushroom tissues (caps, stalks, whole fruit bodies) using flame atomic absorption spectrophotometry.
• Analysis of silver bioconcentration factor (BCF) and correlation with substrate silver levels.

Main Results:

• Silver concentration in mushroom tissues increased with higher silver fortification of the compost (up to 150 mg/kg dry weight).
• A positive correlation (r=0.72) was observed between substrate silver levels and silver content in mushrooms.
• The bioconcentration factor (BCF) for silver was inversely correlated with substrate silver concentration, with highest BCFs at the lowest fortification (0.01 mg/kg).

Conclusions:

• Agaricus bisporus effectively accumulates silver from contaminated substrates.
• Silver uptake is dose-dependent on substrate concentration, but BCF is highest at low concentrations.
• Silver nitrate, up to 10.3 mg/kg, did not exhibit observable toxicity to mycelial growth or fruiting in A. bisporus.