The effect of different submerged culture conditions (medium composition, pH and temperature) on mycelium biomass and production of intracellular polysaccharides (IPS) by the valuable edible and medicinal mushroom Lentinula edodes was investigated. In total, 12 carbon and 7 nitrogen sources in the nutrient medium were tested. Glucose and peptone were determined to be the most suitable carbon and nitrogen sources, respectively, both for IPS and biomass production. Generally, modified glucose-peptone medium, C/N ratio of 18, pH adjusted to 6.0 and cultivation temperature of 25 °C were found to enhance the yield of biomass and IPS by mycelium of L. edodes IBK 2541 in submerged culture. Selection of medium composition and physical cultivation parameters resulted in an IPS production of 940 mg/l on the modified glucose-peptone medium, which is three-fold higher than that from the basal medium (306 mg/l).

Mycelial sensitivity of higher Basidiomycetes medicinal Ling Zhi or Reishi mushroom, Ganoderma lucidum, to the light of various spectral compositions, beam geometry, and polarization has been studied. G. lucidum cultures showed the greatest sensitivity to blue and red light. Light processing of the inoculum has lowered the quantity needed for inoculation and reduced the duration of the fermentation process. The influence of irradiation on polysaccharide synthesis, carbohydrate composition of exopolisaccharides, and mycelial microstructures of G. lucidum has been investigated. The more pronounced stimulating effect of coherent and pulsed light in comparison with noncoherent and continuous light has been observed.

Mushrooms are known to produce phytohormones, in particular cytokinins. Here we studied in vitro production of cytokinins in medicinal mushrooms. Cytokinins were identified and quantified in mycelial biomass of 13 species by using high-performance liquid chromatography-mass spectrometry. Trans-zeatin, zeatin riboside, zeatin-O-glucoside, isopentenyladenosine, and isopentenyladenine were found but only 1 species (Ganoderma lucidum) contained all these forms. Zeatin-type cytokinins predominated. Composition of the cytokinin pool was unique in each species. The largest total amount of cytokinins was detected in Morchella esculenta strain 1755 and the smallest amount, in Flammulina velutipes strain 1878. The productivity of cytokinin biosynthesis in mycelial biomass of mushrooms was the lowest in mycelial biomass of Sparassis crispa strain 314 and highest in Pleurotus ostreatus strain 551. F. velutipes strain 1878 and Cyclocybe aegerita strain 960 mycelial biomass showed the most productive zeatin riboside biosynthesis. We emphasize the need to take into account the biological activity of cytokinins, on the basis of the mycelial biomass of medicinal mushrooms, in the development of drugs or dietary supplements. Macromycetes with high rates of cytokinin biosynthesis are considered to be prospective producers of pharmacologically active compounds.