Grape pomace is the production residue of wineries rich in bioactive phenolic compounds. In this study, grape pomace of red grape varieties was used as a substrate for the cultivation of eleven different filamentous fungi (Trametes versicolor TV6, Trametes versicolor TV8, Trametes versicolor AG613, Trametes gibbosa, Phanerochaete chrysosporium, Ceriporiopsis subvermispora, Pleurotus eryngii, Ganoderma lucidum, Ganoderma resinaceum, Humicola grisea, and Rhizopus oryzae) under solid-state fermentation conditions with the aim of investigating their influence on the recovery of phenolic compounds. By screening the profile of phenolic compounds in the extracts obtained before and after biological treatment of grape pomace, a total of 21 phenolic compounds were identified and quantified. It was found that biological treatment of the frankovka sample with R. oryzae increased the recovery of most phenolic compounds (by 1.1 – 2.4-fold compared to the yield in the biologically untreated sample). The same process conditions were used to scale-up the process in a tray bioreactor, where a 1.1 – 2.5-fold increase in the recovery of the tested phenolic compounds was achieved compared to the yield in the biologically untreated sample. During fermentation, the activity of hydrolytic enzymes (β-glucosidase, xylanase, cellulase, invertase) was measured, of which the enzyme xylanase had the highest activity (62.96 U/gdb in laboratory jars and 47.67 U/gdb in a tray bioreactor) and the lignolytic enzymes (laccase, manganese peroxidase, lignin peroxidase) which had relatively low enzymatic activities. During fermentation in a tray bioreactor, a strong positive correlation was observed between stilbene and lignolytic enzymes and xylanase (r > 0.7). R. oryzae transformed grape pomace and reduced its mass by 17.58 %.