Efficient production and skincare activity evaluation of schizophyllan, a β-glucan derived from Schizophyllum commune NTU-1

Schizophyllan (SPG), a β-glucan produced by the fungus Schizophyllum commune, possesses a β-(1 → 3)-linked backbone with single β-(1 → 6)-linked glucose side chains at approximately every third residue. In this study, we screened SPG-producing strains of S. commune from different provinces in China. A candidate strain (NTU-1) with a high SPG yield was chosen, and the fermentation conditions were optimized. The optimal carbon and nitrogen sources were sucrose (40 g/L) and yeast extract (20 g/L), respectively. The optimal conditions for pH and temperature were 5.0 and 28 °C, respectively. Inclusion of 0.2 mg/L of 2,4-Dichlorophenoxyacetic acid in the medium further increased the SPG concentration. In a 5-L bioreactor, the fermentation cycle was reduced from the initial seven days to five days, and the concentration of SPG obtained was 21.3 g/L, which is the highest reported to date. In addition, we evaluated the bioactivity of the SPG prepared using strain NTU-1. The results showed that SPG had certain characteristics of anti-oxidation, anti-photoaging, and inhibition of melanin production, making it a promising reagent for skin care.