INFLUENCE OF NITROGEN CONCENTRATION ON PHOTOINDUCED GROWTH, ENZYMATIC ACTIVITY AND MELANINE SYNTHESIS BY Inonotus obliquus (Ach.:Pers.) Pilát

The aim of the work was to study the effect of nitrogen concentrations on photo-induction of growth, enzymatic activity and synthesis of melanin by the medicinal fungus Inonotus obliquus (Ach.: Pers.) Pilát from the Collection of cultures of cap mushrooms of Kholodny Institute of Botany of the National Academy of Sciences of Ukraine. Irradiated by light of low intensity, different coherence and in different wavelength ranges, mycelium was cultivated in a dynamic mode on a glucose-peptone medium with different concentrations of total nitrogen. The concentration of the nitrogen source was not shown to significantly affect the photo-induced stimulation of the growth of I. obliquus. The increase in biomass accumulation of mycelium photoactivated in different modes was almost the same in all variants of the experiment, compared with the biomass of not-irradiated mycelium. A reliable dependence of the photo-stimulation of melanin synthesis on the concentration of nitrogen in the medium was established. Reduced nitrogen concentration more than twice increased the stimulating effect of low-intensity laser radiation with a wavelength of 488 nm. Using substrate with a reduced content of the nitrogen source is advisable to increase the photo-induced stimulating effect in the production of extracellular catalase, tyrosinase and polyphenol oxidase, intracellular peroxidase. Thus, the cultivation parameters of I. obliquus and the light treatment regimes of the inoculum should be adjusted according to the target bioactive components.