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Purpose. To reveal the influence of the substrate compositions on technical indicators and the chemical composition of the fruiting bodies of the golden oyster mushroom and poplar mushroom. Methods. The experimental design included cultivation of two species of wood-decay fungi Pleurotus citrinopileatus Singer (strain 2161 IVK) and Cyclocybe aegerita (V.Brig.) Vizzini (strain 2230 IVK) on three variants of substrate composition. Laboratory, laboratory-production methods for evaluating the effectiveness of growing technology, chemical composition of the obtained raw materials, statistical methods of analysis were applied. Results. The structure and composition of substrates affect the technological characteristics of the culture, physical and chemical properties of fruiting bodies. The shortest fruiting cycle of 35.2 ± 1.7 days was determined for C. aegerita under growing conditions on SC1 substrate which formula included «straw, husks, pellet, rapeseed, corn, and CaCO3» in the ratio of 30: 40: 70: 20: 20: 1. The highest yield (170.5 ± 15.2 g per 1 kg of substrate) in the experiment was determined for P. citrinopileatus on the SC1 substrate composed of «straw / pellets  / rapeseed / corn / CaCO3» in the ratio 40: 90: 20: 25: 1. Fruiting bodies of P. citrinopileatus obtained from the SC3 substrate composed of  «pellets / rapeseed / corn / CaCO3» in the ratio 60: 110: 20: 30: 1 had the highest protein content – 22.47 ± 0.19%, and fruiting bodies from the SC1 substrate had the least amount of proteins – 17.38 ± 2.60%. Fruiting bodies of C. aegerita contained more lipids than those of P. citrinopileatus, but the factor of the influence of the substrate composition on the total amount of lipids for some cultivars was insignificant. The largest amount of endopolysaccharides was isolated from the fruiting bodies of C. aegerita (6.81 ± 0.41%) cultivated on SC3 substrate, and the smallest in the SC1 variant (1.38 ± 0.25%). The content of endopolysaccharides in the fruiting bodies of P. citrinopileatus had less variability from 2.54 ± 0.54 (SC3) to 4.72 ± 0.61% (SC1). Conclusion. Substrate compositions significantly affect the biological efficiency of cultivars and the content of nutrients in fruiting bodies of the studied species. The obtained results enable producers of mushrooms to predict the production efficiency and quality of grown mushrooms in accordance with the use of available raw materials.

Quality spawn, which is also dependent on grain composition, is a critical factor that must be optimized to achieve successful and profitable mushroom farming. The characteristics of grain spawn composition (Factor A) and two microclimatic fruiting conditions (Factor B) were studied in the cultivation of <em>Pleurotus ostreatus</em>. Eight different grain material combinations (GMC1-8) made from wheat, barley, oat, and millet were used to prepare spawn and tested for mushroom cultivation under unregulated and regulated fruiting conditions. The physicochemical characteristics of the different grain spawn, substrate, time to attain the first flush, and BE (biological efficiency) in the different GMCs under the two fruiting conditions were determined. The differences in nutrient compositions of the GMCs tested did not result in a significant difference in the nutrient composition of the cultivation substrate. GMCs containing barley and oat gave BE values that were not significantly different under the two microclimatic conditions tested. GMCs containing 100 % wheat and millet resulted in the poorest BE recorded. However, equal combination of wheat, barley, and oat (GMC8) gave the best results among GMCs tested. Furthermore, it is more cost-efficient to use the GMC8 combinations since wheat is cheaper than all other grains tested.

The “poplar” mushroom C. aegerita has fruiting bodies that are attractive for their appearance and tasty properties. It is also known that mushrooms contain unique substances, especially proteins, polysaccharides, and aromatic terpenes with enhanced nutritional and medicinal value. However, the lack of a well-founded technology of cultivation using available agriculture wastes interferes with the domestic market saturation with this mushroom. Three strains of C. aegerita from the IBK mushroom culture collection were investigated on the possibility of introducing them into the industrial culture. The vegetation cycle of strains 2230 and 2231 was found to have a duration of 42 days versus 46-64 days for the previously studied strains. The highest yield was obtained in the study for strain 2231, which yielded from 217 to 220 grams per kilogram of the substrate during three cycles of cultivation. The biological efficiency of the strains as a result of the first fructification flush was from 20,2 (2229) to 60.4 % (2231), which is in agreement with the published data of other investigators. The external appearance was described in detail and parameters of fruiting bodies of strains were analyzed, which differed from each other both by shape and size. Microclimatic conditions for the study, strains 2230 and 2231 had brown caps, whereas the formed fruiting bodies of strain 2229 were distinguished by a pleasing milky cream color. The heaviest fruiting bodies were formed in strain 2229 (7.5±0.4 g), which was an average of 2 g higher than the weight of fungi of other strains studied. The highest fruiting bodies were found in strain 2230 at a height of 91.0±1.8 mm, which also had the widest cap with a 29.5±0.9 mm diameter. The greatest diameter of the stipe, reaching an average of 10.8±0.3 mm, was observed in fruiting bodies of strain 2229. The variability of morphological characters and the tendencies in the number of fruiting bodies of a certain size in the total volume of harvested mushrooms were investigated, which can help in the design of packing and marketing measures.