Optimized Liquid Medium Formulation for Sanghuangporus vaninii and Biological Activity of the Exopolysaccharides

Abstract

Aims: Sanghuangporus vaninii (S. vaninii) is a rare medicinal mushroom that is rich in polysaccharides, triterpenes, flavonoids, and other bioactive compounds. It has good potential development value. Methods and Results: We performed single factor experiments and Box-Behnken response surface methodology to optimize the liquid fermentation medium formulation for S. vaninii with mycelial biomass as the indicator. The in vitro antioxidant and anti-cancer capacity of the exopolysaccharides of S. vaninii were estimated. The optimal liquid fermentation media composition for the MS-4, MS-6, and MS-8 strains of Sanghuangporus vaninii consisted of 25.86 ± 0.068 g/L maltose, 7.3 ± 0.043 g/L yeast extract, and 0.71 ± 0.005 g/L dandelion powder. The average mycelial biomass of S. vaninii under optimal conditions was 12.61 g/L. The mycelial biomass of the Sanghuangporus vaninii strains in the optimized formulation was 109–191% higher than that obtained with the basic potato dextrose broth (PDB). The exopolysaccharides of Sanghuangporus vaninii exhibited an ABTS radical scavenging activity with an EC50 of 0.021 ± 0.017 mg/mL and a DPPH radical scavenging activity with an EC50 of 0.076 ± 0.043 mg/mL. In anti-cancer assays, these exopolysaccharides demonstrated an IC50 value of 1.98 ± 0.36 mg/mL against PC-3 human prostate cancer cells, indicating significant bioactivity, highlighting their potential as functional food ingredients. Conclusions: In this study, the formula of liquid fermentation of S. vaninii strains was optimized, which lays a theoretical foundation for increasing the yield of S. vaninii and its application in industry. Moreover, our data showed the clinical potential of the S. vaninii exopolysaccharides as antioxidants and anti-cancer drugs.