Morus celtidifolia and Its Natural Endophyte Fusarium concentricum DL32 as New Sources of Resveratrol

The levels of resveratrol (RV) were determined in Morus celtidifolia. Simultaneously, a new RV-producing strain of Fusarium concentricum (DL32) was isolated and characterized from this plant. Batch cultures of F. concentricum DL32 developed in potato dextrose broth (PDB) added with peptone (10 g/L) as a nitrogen source revealed its ability to biosynthesize and release trans-RV to the culture media. The assessment of amino acid precursors (50-500 mg/L; tyrosine and phenylalanine) and six different elicitors (20-200 mg/L; cellulase, methyl jasmonate, salicylic acid, ergosterol, thymol, and citral) on batch cultures suggested that tyrosine, cellulase, salicylic acid, and ergosterol significantly increased RV production (p < 0.01) associated with biomass accumulation. Optimized batch cultures developed in PDB (pH 7, 25°C, 50 g/L glucose, 150 rpm,10 g/L peptone), enriched with 400 mg/L tyrosine, 100 mg/L cellulase, 200 mg/L salicylic acid, and 200 mg/L ergosterol, increased RV production from 46.6 to 506 µg/L.