Efficient biocatalysis of trillin through recombinant enzyme hydrolysis for clean diosgenin production

Abstract Diosgenin has been widely used as a precursor in the pharmaceutical industry. The conventional diosgenin production method, direct acid hydrolysis, can cause severe environmental pollution and has low production efficiency. In this study, the β-glucosidase FBG1 was successfully over-expressed in Pichia pastoris. The engineered yeast was grown in 5- and 50-L bioreactors to a high-cell-density, and the resulting recombinant FBG1 without purification was directly used for trillin biocatalysis. A novel enzymatic biocatalysis method was established through efficient biocatalysis of trillin by recombinant FBG1 and a practical diosgenin purification process. Diosgenin production reached ∼1.7 mg/mL under optimized biocatalysis conditions with a corresponding ∼94 % trillin conversion. The production process was further scaled up from 2 mL to 20, 200, and 2000 mL working volumes, producing equivalent efficiency. This recombinant enzyme biocatalysis process resulted in ∼680 mg diosgenin when 1 g trillin was processed, together with ∼90 % environmental impact elimination and ∼36 % cost reduction. Enzymatic biocatalysis can convert trillin into a high-value-added pharmaceutical precursor of diosgenin with high eco-efficiency, cost-effectiveness, and sustainability is presented here for the first time and is a promising method for future applications in industrial processes.