Nanoparticles synthesis by Agaricus soil basidiomycetes

Abstract

We examined the effect of various concentrations of HAuCl4, AgNO3, Na2SeO3, Na2SiO3, and GeO2 on mycelial growth of the soil basidiomycetes Agaricus bisporus and A.arvensis in submerged and solid media. Fungal mycelial extracts and cell-free culture filtrates were able to reduce ions of Au, Ag, Se, Si, and Ge compounds, forming Au0, Ag0, Se0, Si0/SiO2 and Ge0/GeO2 nanoparticles. The physical characteristics of the mycogenic nanoparticles differed depending on the species of Agaricus and the type of extract. Au nanospheres obtained with cell-free culture filtrates were of 2-5nm diameter in A.bisporus and of 2-10nm in A.arvensis. Nanoparticles produced by extracts of mycelia were several times larger and highly heterogenous. Ag nanoparticles produced by cell-free culture filtrates were spherical or irregular-shaped and agglomerated, whereas with extracts of mycelia, small homogenous nanospheres of 1-10nm were formed. Se nanospheres obtained with cell-free culture filtrates were of 100-250nm diameter in A.bisporus and of 150-550nm diameter in A.arvensis. The particles synthesized with extracts of mycelia were of 40-140nm in A.bisporus and of 100-250nm in A.arvensis. Incubation of Na2SiO3 with cell-free culture filtrates resulted in porous Si nanoparticles of 30-65nm in A.bisporus and of 50-200nm in A.arvensis. Ge nanoparticles synthesized by both Agaricus species were mostly spheres of 50-250nm diameter.