Effect of colloidal solutions of metal nanoparticles and laser irradiation on biological activity of the edible medicinal macrofungus Pleurotus eryngii (Pleurotaceae, Agaricales) in vitro

Aim. The goal of our work was to study the effect of colloidal solutions of metal nanoparticles (NPs) on the synthesis of mycelial mass, polysaccharides, phenolic compounds, and the antioxidant activity of the edible medicinal macrofungus Pleurotus eryngii, as well as the effects of photocatalytic activity of NPs after exposure to low-intensity laser radiation under submerged cultivation conditions. Methods. Traditional mycological methods and unique photobiological methods were used. The effect of light on the biosynthetic and biological activity of P. eryngii was studied using low-intensity coherent monochromatic blue laser light ( = 488 nm). The experiment used colloidal solutions of metal nanoparticles (FeNPs, MgNPs, AgNPs) based on the method of volumetric electric spark dispersion of metals patented in Ukraine. Results. Treatment of the inoculum with colloidal solutions of FeNPs and MgNPs increased the amount of mycelial mass of P. eryngii by 38–53%, while irradiation of the inoculum with blue laser light ( = 488 nm) in a medium with NPs increased the growth activity of the P. eryngii mycelium by 6.8–18.2%. All nanoparticles suppressed the biosynthesis of extracellular polysaccharides. The most significant effect was observed with the addition of MgNPs — 21.4%. While the use of photoinduced nanoparticles stimulated the synthesis of extracellular polysaccharides, the most excellent effect was observed for MgNPs — 100%. The addition of all NPs to the P. eryngii inoculum reduced the amount of intracellular polysaccharides in the mycelial mass by 9.4% (MgNPs) and by 22% (AgNPs). The use of NPs photoinduced by blue laser light increased the amount of intracellular polysaccharides in the mycelial mass of P. eryngii by 28.1% (AgNPs) and by 50% (MgNPs). Treatment of the inoculum with colloidal solutions of AgNPs, FeNPs and MgNPs and laser light-induced nanoparticles increased the amount of phenolic compounds in the mycelial mass. The highest total phenolic content (TPC) values in ethanol extracts were recorded when using photoinduced MgNPs — 59.51±0.4 mg GAEs/g dry mass. Conclusions. The results of the studies provided grounds to consider metal nanoparticles (FeNPs, MgNPs), and lowintensity blue laser radiation as promising regulators of the synthesis of polysaccharides and phenolic compounds in the mycelial mass of P. eryngii under submerged cultivation conditions.