The influence of different compounds of trace elements on the biomass and synthesis of exopolysaccharides of mycelium Trametes versicolor (Polyporaceae, Polyporales)

Abstract

This article presents the results of research on the influence of citrates of zinc, manganese and copper, obtained by the method of aquanotechnology, on a number of physiological indicators of a valuable medicinal mushroom Trametes versicolor 353. Previously we detected that these metal citrates stimulated the growth of mycelium more intensively than sulfates of the above-mentioned metals in equal concentrations. In the present research we investigated the influence of these metal citrates on the parameters of assimilation of carbon and nitrogen sources, metal ion accumulation and synthesis of exopolysaccharides. The degree of metals ions accumulation in the mycelium was studied by the method of optical emission spectroscopy with an inductively coupled plasma. The economic coefficient of biomass synthesis and impact of nitrogen assimilation were higher on media with the metals citrate than on the medium with the sulfates of the studied metals. Thus, the highest economic coefficient of biomass synthesis (36%) was observed on the medium with copper citrate. Also, copper citrate (amongst the studied metals) increased the level of assimilation of the nitrogen source by up to 35%, versus 18% on the control medium. Quantitative analysis of trace elements in biomass showed that the mycelium accumulated an equal amount of zinc or manganese ions on both types of media (with citrate or sulfate of these metals). However, on the medium with copper citrate, mycelium of T. versicolor 353 accumulated copper ions better then on a medium with copper sulfate: 82.9 μg/g of biomass on the medium with copper sulfate versus 162.0 μg/g of biomass on the medium with copper citrate. Also the results show that a significant increase of biomass (by 79% relative to the control) on the copper citrate medium is due to a threefold reduction of the exopolysaccharides amount. This data indicates a greater biological activity of copper citrate, relative to copper sulfate. Only zinc citrate raised both the synthesis of biomass and the synthesis of exopolysaccharides by 37% and 29% respectively ( relative to the control trial).