High-titer production of myo-inositol by a co-immobilized four-enzyme cocktail in biomimetic mineralized microcapsules

Myo-inositol is widely used in food, feed, pharmaceutical and cosmetic industries, but its great potentials are restricted from its limited supplies and high prices. Inositol is the first biobased product produced by the in vitro biomanufacturing platform containing multi-enzymes in one pot on an industrial scale. However, the in vitro multi-enzyme-based biomanufacturing face the challenge of enzyme deactivation and high cost of the enzymes used. To further prolong the enzyme lifetime and decrease its biomanufacturing cost, here we developed a co-immobilized four-enzyme cocktail using biomimetic mineralized microcapsules composed of polyethyleneimine and silicate for large-scale production. The lumped enzyme half-life of the microcapsules was 55.5 h at 70 °C, which was 5.9 folds of that of the four-enzyme cocktail. An inositol titer of up to 210 g/L was produced, and the cost of enzymes used was decreased by 3.4 times. This is the first attempt to realize high-titer production of inositol by co-immobilized multi-enzymes, laying a foundation of in vitro biomanufacturing based on in vitro synthetic enzyme biosystems.