Optimization of Fermentation Conditions in Ergothioneine Biosynthesis from Ganoderma resinaceum (Agaricomycetes) and an Evaluation of Their Inhibitory Activity on Xanthine Oxidase.

Ganoderma resinaceum is a traditional mushroom that contains natural products, including ergothioneine (EGT), which has powerful antioxidant properties in the human body. To increase EGT yield from G. resinaceum, the optimal carbon and nitrogen sources in the culture medium were determined as 20 g/L sucrose and 4 g/L NH4Cl, respectively. The fermentation conditions were then optimized using response surface methodology, with the highest EGT yield of approximately 4.10 mg/L achieved at an initial pH of 5.19, a culture medium volume of 118 mL, and a fermentation temperature of 26.90°C. After extraction, EGT was purified using Sephadex G-10, resulting in a purity of 43.72%. Both the crude and purified EGT extracts were evaluated for their inhibitory activity against xanthine oxidase in vitro, with positive results. These findings suggest the potential for developing edible fungi-derived medicines to treat gout, which could alleviate the side effects of traditional medicines.