NAD+ · research summary

Systems metabolic engineering of a plasmid-free Escherichia coli cell factory for high-level cytidine production.

Synthetic and systems biotechnology · 2027. Summary drawn from the study's full text. Each statement is followed by the exact sentence it comes from. This is a research summary, not medical advice.

Study type

Systems metabolic engineering study constructing a plasmid-free E. coli cell factory for cytidine production.
“In this study, a plasmid-free E. coli cell factory was constructed through systems metabolic engineering.”

Subjects

Engineered Escherichia coli strains (specifically strain cyt 23) derived from the W3110 parental strain.
“E. coli W3110 served as the parental strain for all genetic modifications, and E. coli DH5α was used for plasmid construction and cloning.”

Sample size

Data presented as the mean ± standard deviation of three independent experiments.
“Data are presented as the mean ± standard deviation of three independent experiments.”

Duration

Fed-batch fermentation in a 5 L bioreactor was conducted for 50 hours.
“The final strain cyt 23 produced 96.20 g/L cytidine in 50 h in a 5 L fed-batch bioreactor.”

Reported findings

Scaffold-based enzyme assembly reduced uridine formation by 98.70%.
“Scaffold-based assembly of PyrF, PyrHD93A, NudG, and PHM8sce using CipA/CipB further improved local pathway channeling and reduced uridine formation by 98.70%.”
The final strain cyt 23 achieved a cytidine titer of 96.20 g/L with a glucose conversion yield of 0.38 g/g.
“The final strain cyt 23 produced 96.20 g/L cytidine in 50 h in a 5 L fed-batch bioreactor, with a glucose conversion yield of 0.38 g/g and productivity of 1.92 g/(L·h).”
Dynamic regulation of respiratory-chain modules using the ydaO motif balanced ATP supply and NAD+ regeneration.
“Finally, an ATP-responsive ydaO motif regulatory module was used to dynamically control respiratory-chain and oxygen-utilization modules, coordinating ATP supply with NAD+ regeneration.”

Source: PubMed 42861367 · DOI 10.1016/j.synbio.2026.09.003 · all study summaries

Reported findings

Scaffold-based enzyme assembly reduced uridine formation by 98.70%.

“Scaffold-based assembly of PyrF, PyrHD93A, NudG, and PHM8sce using CipA/CipB further improved local pathway channeling and reduced uridine formation by 98.70%.”

The final strain cyt 23 achieved a cytidine titer of 96.20 g/L with a glucose conversion yield of 0.38 g/g.

“The final strain cyt 23 produced 96.20 g/L cytidine in 50 h in a 5 L fed-batch bioreactor, with a glucose conversion yield of 0.38 g/g and productivity of 1.92 g/(L·h).”

Dynamic regulation of respiratory-chain modules using the ydaO motif balanced ATP supply and NAD+ regeneration.

“Finally, an ATP-responsive ydaO motif regulatory module was used to dynamically control respiratory-chain and oxygen-utilization modules, coordinating ATP supply with NAD+ regeneration.”