Study on the production and structure of a novel <i>Tremella fuciformis</i> polysaccharide by fermentation

A novel Tremella fuciformis polysaccharide (TP) was identified, and its production, structural characteristics, and antioxidant activity were systematically investigated. The production of fermented TP (FTP) was optimized by modulating medium composition and fermentation conditions in a 5 L bioreactor. The maximal FTP yield (36.50 ± 1.20 g/L, n = 3) was achieved using a medium containing 60 g/L sucrose, 8 g/L corn steep liquor, 1 g/L MgSO₄, and 3 g/L KH₂PO₄, fermented at 25 °C for 96 hours under a constant sucrose feed-rate fed-batch strategy. Structural analyses revealed that FTP possesses a unique furanose glycosidic linkage and a triple-helix conformation, features absent in extracted TP (ETP). Additionally, FTP contained a greater diversity and higher content of uronic acids compared to ETP, confirming its classification as a novel TP. Comparative assessment of antioxidant activity demonstrated that FTP exhibited stronger antioxidant properties than ETP, suggesting its enhanced potential as a functional bioactive ingredient for food application.