This study evaluated the effects of supplementing sawdust medium with 10% (w/w) Korean-style soy sauce residue (KS) and brewed soy sauce residue (BS) on the cultivation of Pleurotus ostreatus. Over 25 days, KS treatment produced mycelial growth comparable to the control, whereas BS treatment showed slower colonization. Fruiting bodies appeared after nine days in the control, ten days with BS, and twelve days with KS, with fresh weights of 146.0 g, 174.8 g, and 89.0 g, respectively, indicating reduced yield with KS and increased yield with BS. In antioxidant assays, DPPH radical scavenging slightly increased from 89.15% in the control to 89.99% with KS and 90.34% with BS. ABTS scavenging was 82.36% in the control, 83.42% with KS, and 75.99% with BS. Total polyphenol content was 64.39 mg AAE/mL in the control, 62.72 mg AAE/mL with KS, and 43.28 mg AAE/mL with BS. In conclusion, KS supports mycelial growth without compromising DPPH-based antioxidant capacity, while BS enhances fruiting body yield but reduces ABTS activity and phenolic content. Both residues show potential as supplementary nutrients in conventional sawdust media.

In this study, we investigated the microbial community of oyster mushrooms at different growth stages at the species level. Gram-positive bacteria were predominant in the presterilized medium. On the other hand, Gram-negative bacteria were predominant in the culture-completed medium, post-harvest medium, and fruiting bodies. In addition, Pseudomonas tolaasii, which is known to cause disease in mushrooms, was confirmed in the cultured medium, post-harvest medium, and fruiting bodies, and it was determined that the mycelium culture stage was contaminated, and the reason why no disease occurred was Sphingobacterium psychroaquaticum. It was confirmed that this was because the growth of Pseudomonas tolaasii was suppressed by producing a component called tolacin. As a result of confirming the diversity of microorganisms, it was confirmed that the presterilization medium contains a variety of microorganisms compared to other growth stages, and the diversity decreases in the order of culture completion medium, fruiting body, and post-harvest medium. showed a trend. As a result of microbial similarity analysis, it was confirmed that the cultured medium and the post-harvest medium showed similar microbial communities, and in the case of fruiting bodies, there were some similarities but overall differences.