In vitro cultures and fruiting bodies of culinary-medicinal Agaricus bisporus (white button mushroom) as a source of selected biologically-active elements

Concentrations of the chosen elements (Cu, Zn, Mg, Fe, Cd and Ni) in fruiting bodies of Agaricus bisporus, in mycelium from in vitro cultures of this species, and in mycelium from in vitro cultures with the addition of L-tryptophan and Zn hydroaspartate to the medium were measured by the Atomic Absorption Spectroscopy Method (AAS). Fruiting bodies of A. bisporus contains a high level of Mg, its concentration ranging from 1545.00 to 2275.00 mu g g(-1) DW. The concentration of Mg in in vitro cultures was at a similar level. With the addition of Zn to the culture medium, a substantial increase of Mg accumulation was observed. Zn was present in the fruiting bodies of A. bisporus in the concentration range 70.39-112.75 mu g g(-1) DW. Enrichment of the culture medium with L-tryptophan increased the bioavailability of Zn by two-fold in in vitro culture. The concentration of Fe in the fruiting bodies of A. bisporus was in a wide range: 13.90-161.75 mu g g(-1) DW. For the substrate enrichment with L-tryptophan, Fe concentrations ranged between 118.65 and 311.65 mu g g(-1) DW. Fruiting bodies of A. bisporus were characterized by different levels of Cd (0.06-4.76 mu g g(-1) DW). In vitro cultures levels of Cd were recorded at a lower level than in the fruiting bodies (0.04-1.08 mu g g(-1) DW). Mycelia of A. bisporus cultured in vitro constitute a good source of the selected biologically-active elements. The method of in vitro cultures proposed here proved that the essential micronutrients are effectively taken up and accumulated in the mycelia.