In this study, we aimed to compare the mycelial growth of Pleurotus ostreatus after medium supplementation with various amino acids at different concentrations to select the optimal medium nutrient composition for mycelial growth. The mycelial growth of P. ostreatus was investigated after adding four amino acids (tryptophan, threonine, methionine, and lysine) at 0.5% or 1% to the medium.The rate of P. ostreatus mycelial growthwas faster in the potato dextrose agar (PDA) medium supplemented with threonine at 0.5% or 1% than that of the control, whereas it was inhibited by tryptophan treatment. Supplementation of sawdust mediumwith all amino acids, except tryptophan, at 0.5% did not alter the mycelial growth, compared to the controls. However, addition of any amino acid to sawdust medium at a higher concentration (1%) inhibited the mycelial growth. The laccase acitivity of P. ostreatus mycelium cultured in PDA medium was the highest when threonine was added, and the lowest when tryptophane was added, consistent with the results of the mycelial growth. Therefore, the addition of threonine, methionine, or lysine to PDA medium at a concentration of 0.5-1%was effective for increasing the mycelial growth of P. ostreatus; however, it inhibited mycelial growth insawdust medium, suggesting that the effects of amino acids dependedon the medium nutrient composition.

This study was conducted to investigate the growth and antioxidant activity of Pleurotus ostreatus mycelia grown in medium supplemented with Aronia. The diameter and dry weight of the mycelia were increased in the medium supplemented with Aronia compared with the untreated medium. The total polyphenol content of mycelia grown in medium supplemented with Aronia and untreated medium was 6.54 mg GAE/g and 5.77 mg GAE/g, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 61.81% and 49.65%, respectively. Moreover, the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 59.83% and 52.66%, respectively. These results confirmed that P. ostreatus mycelial growth and antioxidant activity were increased when Aronia was added to the culture medium.