Extracellular mycosynthesis of silver nanoparticles and their microbicidal activity

Myconanotechnology, a combination of mycology and nanotechnology that deals with the synthesis of nanoparticles using fungi or their metabolites, has great potential in the area of agriculture owing to the high surface-to-volume ratio and excellent biomedical, electronic, mechanical and physicochemical properties of these myconanoparticles. Extracellular mycosynthesis of Aspergillus flavus (KF934407) silver nanoparticles (AgNPs) was performed, which were produced by redox reaction. Furthermore, the extracellular synthesised AgNPs were characterised by ultraviolet/visible spectrophotometry, differential light scattering (DLS) and transmission electron microscopy. The bactericidal and fungicidal actions of synthesised silver myconanoparticles (myco-AgNPs) were studied against pathogenic bacteria and fungi. The formulated myco-AgNPs were spherical in shape, with a size in the range of 50nm and DLS at an intensity of 107.8nm. The myco-AgNPs showed effective antimicrobial properties against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Trichoderma spp. at high concentrations. In conclusion, AgNPs have a prolonged microbicidal effect as a result of continuous release of Ag⁺ at sufficient concentrations. Thus, A. flavus-based myco-AgNPs have the potential to be used as a non-toxic and cheap antimicrobial agent against various pathogenic bacteria and fungi.