How was the NMN biosynthetic pathway implemented in E. coli for intracellular production?

The pathway was engineered into E. coli KQ_BG001, a strain capable of metabolizing glucose to produce cytidine endogenously. The enzymes PyNP and NRK were expressed in the cytidine-producing strain to establish a de novo biosynthesis pathway from glucose to NMN.

From: "Novel Biosynthetic Pathway for Nicotinamide Mononucleotide Production from Cytidine in Escherichia coli", Catalysts 2025, 15(9), 816;

The NMN biosynthetic pathway was implemented in E. coli by expressing PyNP and NRK in a cytidine-producing strain. Optimization of induction and fermentation conditions led to NMN production reaching 33.71 mg/L, demonstrating the functional implementation of the pathway in vivo.