Efficient Biosynthesis of Gastrodin by UDP-Glycosyltransferase from <i>Rauvolfia serpentina</i>

Gastrodin, the primary bioactive constituent of <i>Gastrodia elata</i>, possesses numerous remarkable pharmacological properties. In this investigation, UDP-glycosyltransferase from <i>Rauvolfia serpentina</i> (RsUGT) was expressed, subsequently purified and characterized. The maximum yield of the enzyme was 17.57 mU/ml and possessed a relative molecular weight of approximately 77.7 kDa. Utilizing GST affinity resin, RsUGT was purified 20.8-fold, with an overall recovery rate of 58.6% and specific activity of 79.2 mU/mg. The optimal temperature and pH for RsUGT was identified as 40°C and 10.0, respectively. Notably, 2% DMSO could increase the RsUGT activity by 12.15%. The Michaelis-Menten constants <i>K</i>_M and <i>V</i>_max were determined to be 0.50mM and 171.60 mU/mg. By optimizing the conditions for the enzymatic biosynthesis of gastrodin by RsUGT, the highest gastrodin production was 285.35 mg/l, accompanied by a molar conversion rate of 99.67%. In addition, the conditions of gastrodin biosynthesis by recombinant strain BL-RsUGT were also studied. The highest gastrodin production was 225.99 mg/l, and the corresponding <i>p</i>HBA conversion rate was 98.00%. These findings confirmed the promising potential of RsUGT in the production of gastrodin.