Immobilizing D-lactonohydrolase with 3D-printed hollow filaments to improve the enzyme stability and reusability

D-pantothenate is one of the essential micronutrients required by the organism. Stereoselective D-lactonohydrolase (D-lac) can hydrolyze DL-pantolactone into D-pantoic acid, the precursor of D-pantothenate. In this study, the D-lac gene from Fusarium moniliforme was heterogeneously expressed in Escherichia coli. Subsequently, coaxial 3D printing was employed, using sodium alginate containing the recombinant cells and CaCl₂ as printing materials. The coaxial nozzle was used to print hollow filaments for the immobilization of recombinant cells. After optimizing the printing conditions, the printed immobilization cells exhibited higher stability and a wider range of reaction conditions (such as pH and temperature) compared to the free cells. After 20 reaction cycles, the enzyme activity maintained approximately 80% of original. The printed hollow filaments were confirmed by scanning electron microscope (SEM). The microchannel structures and large specific surface of filaments may facilitate substrate exchange and enhance catalytic efficiency. The results indicated that the 3D printed hollow filaments can be used as a potential material for enzyme immobilization.