Culture medium composition influences mycelial growth and metabolite biosynthesis of Daedaleopsis tricolor

The metabolites of the basidiomycete Daedaleopsis tricolor have attracted research attention due to their antioxidant, antimicrobial, and antitumor properties. This study investigated the submerged cultivation of the Daedaleopsis tricolor strain KS11 in nutrient media supplemented with varying nitrogen sources, including yeast extract, soy protein isolate, and a 1:1 combination thereof. The cultivation on the combined medium yielded up to 9 g/L of biomass and reduced the cultivation time by one day compared to media containing a single nitrogen source. The total pool of exometabolites obtained using the combined medium demonstrated high antioxidant (88.61 mg/g) and antiradical activity (3.41 mg/mL). This activity correlated with a high flavonoid content of 18.56 mg/g, which exceeded the levels found in exometabolites from the other media. The use of soy protein isolate as a nitrogen source was more effective for the synthesis of endopigments. These endopigments were identified as melanins by infrared spectrometry. The cultivation of Daedaleopsis tricolor KS11 on a combined medium containing a 1:1 ratio of yeast extract and soy protein isolate represents a promising approach, as it facilitates the concurrent accumulation of exopigments and endopigments with high antioxidant properties. These findings provide a basis for developing dietary supplements with enhanced antioxidant activity.