Arsenic uptake and arsenic compounds in cultivated Agaricus bisporus

In view of recent findings that most wild-growing mushrooms contain mainly organo-arsenic compounds, this work was conducted as a preliminary study of arsenic uptake and the distribution of arsenic compounds in mushrooms grown under controlled conditions with the intention of assessing potential health risks involved in the consumption of cultivated Agaricus bisporus.Agaricus bisporus was grown on substrate containing 1000 mg As kg−1 As(V) as well as on control substrate without arsenic addition. Agaricus bisporus grown on the control substrate (3.8 ± 0.2 μg As/g dry mass) contained 0.50 ± 0.03 μg As/g dry mass, whereas 22.8 ± 1.0 μg As/g dry mass were found in the mushrooms grown on the substrate amended with As(V).Arsenic speciation analysis of extracts of the mushrooms revealed that the main proportion of the incorporated arsenic in the treated Agaricus bisporus was present as inorganic arsenic. In the treated mushrooms the concentration of dimethylarsinic acid was twice as high as in the control mushrooms and the concentration of methylarsonic acid was almost 4 times higher than the concentration in the control mushrooms. Surprisingly, the concentration of arsenobetaine in the treated mushrooms was approximately half the concentration in the control sample.