Potential of the Endophytic Fungus Phialocephala fortinii Rac56 Found in Rhodiola Plants to Produce Salidroside and p-Tyrosol

2-(4-Hydroxyphenyl) ehyl-fi -D-glucopyranoside (salidroside) and 4-(2-hydroxyethyl) phenol (p-tyrosol) are famous food and medicine additives originally derived from alpine Rhodiola plants. Salidroside or p-tyrosol production by the endophytic fungus Rac56 (Phialocephala fortinii) was confirmed by UPLC/Q-TOF-MS and H-1-NMR. The fermentation conditions were optimized by orthogonal design using data processing system software. The broth fermentation results showed that salidroside and p-tyrosol extraction yields from Rac56 were stable and reached 1.729 +/- 0.06 mg and 1.990 +/- 0.05 mg per mL of culture medium, respectively. The optimal conditions for salidroside and p-tyrosol production in fermentation culture of Rac56 were determined to be 25 degrees C, pH values of 7 and 5, Czapek-Dox culture medium volumes of 150 mL and 50 mL in 250 mL flasks, rotation speeds of 100x g and 200x g, and fermentation durations of 7 and 15 days, respectively. Under these optimal conditions, stable yields of 2.339 +/- 0.1093 mg and 2.002 +/- 0.0009 mg per mL of culture medium of salidroside and p-tyrosol, respectively, were obtained, indicating that the P. fortinii Rac56 strain is a promising source of these compounds.