Page 135 - IJB-9-3

International Journal of Bioprinting Programmable formaldehyde dehydrogenase for biodegradation formaldehyde

Figure 6. Catalysis characterization of 3D-printed PFDH/CA microspheres. (A–C) The SEM image of immobilized PFDH/CA microspheres. (A) Free
PFDH. (B) The surface structure of PFDH/CA microspheres. (C) The internal structure of PFDH/CA microspheres. (D) FT-IR spectra for 3D-printed
enzymes, blank (CA), and liquid enzymes. (E–K) EDS elemental mapping of PFDH/CA microspheres. (E) The SEM diagram of the mapping analysis
position. (F) Different colors represent different elements in the general mapping. (G) Map of the distribution of the element N. (H) Map of the distribution
of the element O. (I) Map of the distribution of the element Ca. (J) Map of the distribution of the element Zn. (K) Map of the distribution of the element C.

3D printing technology to shape the immobilized enzyme. and finally immobilized crude enzyme. The results showed
In the first approach, the initial E. coli concentration that 3D printing technology holds significant prospect for
was maintained, the immobilized particles containing the immobilization of PFDH. In application, 3D printing
different objects were printed, and the relative activity of PFDH is aimed at degrading formaldehyde. Compared
of different printed objects were compared. As shown in with printing pure enzyme, the effect of formaldehyde
Figure 8, 57.21% relative activity was obtained when the removal by 3D printing recombinant E. coli is not very
pure enzyme/CA microspheres were recycled for eight different. However, printing recombinant E. coli removes
times. The printed recombinant E. coli/CA microspheres the need of fragmentation and purification for industrial
and the pure enzyme/CA microspheres shared a similar use. The printed recombinant E. coli shows the advantages
trend, with 56.12% relative activity after six cycles. While of reduced cost, high efficiency and good homogeneity,
the effect of printing the crude enzyme/CA microspheres and has broad industrial application prospects. In the
was poor, in general, immobilized pure enzyme has the second approach, CAD modeling software is needed to
best effect, followed by immobilized recombinant E. coli, build different models for the 3D-printed shapes. 3D

Volume 9 Issue 3 (2023) 127 https://doi.org/10.18063/ijb.695