Salidroside, a core secondary metabolite from Rhodiola species, possesses a wide range of pharmacological benefits including anti-fatigue, antioxidant, neuroprotective, immunomodulatory, anti-hypoxia, and anti-tumor activities. It is widely used to alleviate neurasthenia, prevent altitude sickness, protect cardiovascular health, and as a skin-protective ingredient in cosmetics. With continuously growing market demand, developing efficient and sustainable production methods for salidroside has become increasingly important.
Traditional production relies on direct extraction from Rhodiola plants, which is limited by long growth cycles, low extraction efficiency, and high costs. Chemical synthesis offers an alternative but requires strong acids, bases, or heavy metal catalysts, posing environmental risks and complicating purification. In contrast, biocatalytic biosynthesis represents a promising green production route, offering environmental friendliness and sustainability. However, the high cost of the sugar donor UDP-glucose (UDPG) and the poor thermostability of glycosyltransferases have been major bottlenecks for industrial application.
The research team from Jiangnan University constructed a dual-enzyme cascade system using sucrose synthase AtSUS3 and glycosyltransferase AtUGT85A1 from Arabidopsis thaliana. This system couples UDPG regeneration with the glycosylation of tyrosol into salidroside, dramatically reducing cofactor costs. The team first optimized soluble expression through fusion tag and linker engineering: TrxA tag fusion enhanced AtSUS3 activity by 23.72%, while SUMO tag with a rigid (EAAAK)₂ linker improved AtUGT85A1 solubility with minimal impact on activity.
To address the poor thermostability of the glycosyltransferase, the researchers employed semi-rational design using the FireProt computational platform. The resulting S324R mutant exhibited 50.95% higher specific activity and significantly improved thermostability—retaining 48.56% residual activity after 120 minutes at 45 ℃, compared to only 29.67% for the wild type. Kinetic analysis revealed an 88.5% increase in catalytic efficiency (Kcat/Km), while molecular dynamics simulations confirmed enhanced structural rigidity and improved substrate affinity through additional hydrogen bonding.
Finally, the team constructed a recombinant strain co-expressing both enzymes for one-pot biosynthesis. The optimized system achieved 13.61 g/L salidroside with a 90% conversion rate within 10 hours, corresponding to a space-time yield of 1.36 g/L/h. With purified enzymes, the titer reached 19.08 g/L with a space-time yield of 1.91 g/L/h. Preliminary economic analysis indicates a profit margin of 96.86%–97.78%, demonstrating strong commercial potential. This integrated approach—combining solubility enhancement, thermostability engineering, and one-pot catalysis—establishes a balanced, practical platform for industrial salidroside biosynthesis.
The work entitled “Efficient one-pot biosynthesis of salidroside via a dual-enzyme cascade system” was published in Systems Microbiology and Biomanufacturing (published on May 27, 2026).
DOI:10.1007/s43393-026-00501-4