Bioproduction of Gastrodin from Lignin-Based p-Hydroxybenzaldehyde Through the Biocatalysis by Coupling Glycosyltransferase UGTBL1-Δ60 and Carbonyl Reductase KPADH

Gastrodin is a bioactive component of traditional Chinese medicine, exhibiting anti-cancer, anti-inflammatory, antioxidant and neuroprotective properties. It has broad application prospects in health foods, pharmaceuticals and cosmetics. In recent years, the conversion of biomass-derived aldehydes into high-value-added chemicals has garnered widespread attention. In this study, gastrodin was biosynthesized via a dual-enzyme coupling system consisting of UGTBL1-Δ60 and KpADH. Specifically, lignin-derived p-hydroxybenzaldehyde was used as the substrate. First, the glycosylation of p-hydroxybenzaldehyde by UGTBL1-Δ60 yielded p-hydroxybenzaldehyde β-glucoside, generating the glycosylation reaction solution. Subsequently, bioreduction of the glycosylation product by KpADH produced gastrodin. Under the optimal reaction conditions (0.05 g/mL KpADH whole cells, 50 mM glucose, pH 7.5 and 30 °C) a gastrodin yield of 82.8% was achieved within 12 h. Moreover, both UGTBL1-Δ60 and KpADH retained high catalytic activity after multiple reaction cycles. This study establishes a green and efficient biocatalytic approach for gastrodin synthesis, and also provides new insights into the high-value utilization of lignin.