Escherichia coli BL21(DE3) optimized deletion mutant as the host for whole-cell biotransformation of NacetylDneuraminic acid.
Biotechnol Lett
; 45(11-12): 1521-1528, 2023 Dec.
Article
en En
| MEDLINE
| ID: mdl-37688676
ABSTRACT
NAcetylDneuraminic acid (Neu5Ac) is the crucial compound for the chemical synthesis of antiflu medicine Zanamivir. Chemoenzymatic synthesis of Neu5Ac involves N-acetyl-D-glucosamine 2-epimerase (AGE)-catalyzed epimerization of N-acetyl-D-glucosamine (GlcNAc) to N-acetyl-D-mannosamine (ManNAc), and aldolase-catalyzed condensation between ManNAc and pyruvate. Host optimization plays an important role in the whole-cell biotransformation of value-added compounds. In this study, via single-plasmid biotransformation system, we showed that the AGE gene BT0453, cloned from human gut microorganism Bacteroides thetaiotaomicron VPI-5482, showed the highest biotransformation yield among the AGE genes tested; and there is no clear Neu5Ac yield difference between the BT0453 coupled with one aldolase coding nanA gene and two nanA genes. Next, Escherichia coli chromosomal genes involved in substrate degradation, product exportation and pH change were deleted via recombineering and CRISPR/Cas9. With the final E. coli BL21(DE3) ΔnanA Δnag ΔpoxB as host, a significant 16.5% yield improvement was obtained. Furthermore, precursor (pyruvate) feeding resulted in 3.2% yield improvement, reaching 66.8% molar biotransformation. The result highlights the importance of host optimization, and set the stage for further metabolic engineering of whole-cell biotransformation of Neu5Ac.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Aldehído-Liasas
/
Escherichia coli
Límite:
Humans
Idioma:
En
Año:
2023
Tipo del documento:
Article