The Influence of Substrate Composition on Nutritional Content and Biological Activity of Some Pleurotus Mushrooms Extracts

Oyster mushrooms (Pleurotus spp.) are a nutrient-rich functional food, packed with protein, fiber, and bioactive compounds, offering a broad range of therapeutic qualities. This paper reports the findings in terms of crude protein, crude fiber, total polyphenols, total flavones, and some phenolic compounds along with the antimicrobial and antioxidant activities of some Pleurotus mushrooms extracts: P. eryngii, P. ostreatus, and P. columbinus. The integration of brewery-spent grains (BSG) into the nutrient media and culture substrate induced a major statistical increase (p < 0.05) for crude protein, total polyphenols, total flavones, and chlorogenic and caffeic acids as well as antioxidant activity. The lowest inhibition concentration IC50 was recorded for P. ostreatus, followed by P. eryngii and P. columbinus. Among the strains, only P. ostreatus and P. columbinus exerted antimicrobial activity against two pathogens: Staphylococcus aureus and Streptococcus pyogenes. These results add and provide evidence of oyster mushrooms’ nutritional properties and possible positive effects on human health.