Bioconversion of ginsenoside Rb1 to CK by co-immobilizing snailase and β-glycosidase on Zr-MOF prepared in the deep eutectic solvent

Zirconium-based metal-organic frameworks (Zr-MOF) are stable and easily functionalized, yet their synthesis has issues like poor environmental friendliness and restricted mass transfer, limiting applications. In this study, we used choline-based deep eutectic solvents (DES) instead of traditional solvents, with propionic acid (PA) as a modifier. In just 6 h, we successfully created a spherical UNP-66 biocomposite with a defect number of 0.7719. We then prepared an immobilized enzyme by covalently attaching snailase (Sna) and β-glycosidase (β-G) to the carrier using glutaric dialdehyde. It had an enzyme-loading capacity of 158 mg/g. DES sped up the synthesis and reduced enzyme-activity loss. The immobilized enzyme showed good thermal, pH, and storage stability. It efficiently catalyzed Rb1 to CK conversion, with a CK yield of 77.23 %. After 6 cycles, it retained 72.82 % of its initial relative enzyme activity. This DES-based defective MOF synthesis method has significant advantages, opening a new path for green, efficient preparation of high-value natural products.