Transcriptomic and Metabolomic Profiling of Pleurotus eryngii Cultivated on Olive Mill Solid Waste-Enriched Substrates

Olive Mill Solid Waste (OMSW) presents an environmental challenge due to its toxicity and difficulties in its recycling. Prior studies suggest its potential as a substrate ingredient for cultivating edible mushrooms. Here, we investigate how varying OMSW concentrations in the substrate affect the synthesis pathways of α-glucan and β-glucan polysaccharides, alongside transcriptional and metabolic changes in Pleurotus eryngii. We also assessed the mushroom’s protein and nitrogen content. Our results highlight the critical role of substrate composition, demonstrating that the OMSW concentration significantly influences mushroom growth, yield, protein content, gene expression, and metabolite profiles. These findings establish OMSW not only as a viable recycling resource but also as a modulator of health-promoting compound synthesis in P. eryngii.