Alternative substrate materials for mushroom cultivation must be developed due to the unstable supply of the currently used substrates. Threonine acts as a nitrogen source in the substrate used for cultivating mushrooms. Threonine influences food flavor and participates in lipid metabolism and protein synthesis as well as energy metabolism through the tricarboxylic acid cycle. In this study, mushroom cultivation substrate was supplemented with threonine to evaluate the effects of threonine on the growth characteristics of and secondary metabolites produced by Pleurotus ostreatus. Threonine supplementation induced substantial changes in the parameters indicating the quality of fruiting bodies. These findings provide a basis for further research on supplementing substrates with amino acids for cultivating mushrooms.

This study analyzed the effects of different nitrogen sources in substrate composition on the growth of Pleurotus ostreatus, as well as the subsequent changes in flavor and antioxidant activity. The T2, composed of poplar sawdust, beet pulp, cotton seed dregs, and cotton seed coat in a ratio of 40:20:20:20, exhibited the highest yield at 156.6 g. The total polyphenol content and ABTS and DPPH radical scavenging activities were 8.25 mg GAE/g, 70%, and 49%, respectively, showing higher radical scavenging activity compared to the Control and T1. Additionally, varying nitrogen content resulted in distinct aroma patterns and is presumed to influence taste profiles such as sourness, umami, and saltiness.