In Vitro Antimicrobial and Antioxidant Activities of Ethanolic Extract of Lyophilized Mycelium of Pleurotus ostreatus PQMZ91109

The antioxidant and antimicrobial potential of the ethanolic extract of Pleurotus ostreatus PQMZ91109 mycelium was determined based on inorganic and organic nitrogen sources in the culture medium. The presence of ammonium sulfate resulted in a greater accumulation of bioactive compounds compared with the organic ones. This finding was also confirmed by the low values of the ascertained EC50 and minimum inhibitory concentration (MICs). Among the organic sources, peptone followed by corn extract, led to a more important radical-scavenging activity. The extracts selectively inhibited the tested strains, mainly the two of the genus Candida, at an MIC value of 1.25 mg/mL. The antioxidant potential was evaluated by the inhibition capacity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, beta-carotene-linoleic acid, which is the reducing power. In addition, the quantity of the compounds with antioxidant effects confirmed the data obtained, they being present in the extracts.