Engineered Pseudomonas putida KT2440 produces extracellular NMN from glucose and aspartate
In this abstract, engineered Pseudomonas putida KT2440 produced up to 1.28 mM (about 0.43 g/L) extracellular NMN after 96 h of shake-flask cultivation; the authors call this a feasibility result and an alternative chassis for further optimization. [1]
Automatic summary · not editorially reviewed
The key findings
Deleting nicB impaired nicotinic acid degradation and led to 66.2 μM nicotinic acid accumulating in cell extracts; additional deletion of pncC and ushA gave no detectable NMN accumulation. [1]
Overexpressing endogenous nadA, nadB and nadC strengthened precursor supply via the NAD de novo pathway and gave about 0.17 mM NMN in cell extracts; integrating an engineered S. enterica pnuC transporter cassette was associated with pronounced extracellular NMN accumulation. [1]
Strain LW10 produced 1.28 mM extracellular NMN (about 0.43 g/L) after 96 h of shake-flask cultivation in basal salt medium with glucose and L-aspartate. [1]
The source at a glance
- Study type / format
- Abstract of a metabolic engineering study in bacteria
- Population / context
- Engineered Pseudomonas putida KT2440 bacterial strains, including the best-performing strain LW10
- Summary based on
- Study abstract
- Original publication
- August 24, 2026
Blocking nicotinic acid breakdown in P. putida KT2440
The study used a "block-enhance-transport" strategy in Pseudomonas putida KT2440. Deleting nicB impaired nicotinic acid degradation and led to 66.2 μM nicotinic acid accumulating in cell extracts. Deleting the putative NMN-consuming genes pncC and ushA in addition did not produce detectable NMN accumulation.
Supporting source [1]
Precursor supply and transport raised NMN in KT2440
Coexpressing endogenous pncB and an engineered Francisella tularensis nadE enabled low-level NMN formation via a Preiss-Handler pathway-based route. Overexpressing endogenous nadA, nadB and nadC strengthened precursor supply through the NAD de novo pathway and gave about 0.17 mM NMN in cell extracts. Chromosomal integration of an engineered Salmonella enterica pnuC transporter cassette was associated with pronounced extracellular NMN accumulation. Extra overexpression of downstream NAD metabolism or phosphoribosyl pyrophosphate supply genes did not considerably improve production, possibly due to metabolic competition or expression burden.
Supporting source [1]
Best strain LW10: 1.28 mM NMN in shake flasks
The best-performing strain, LW10, produced 1.28 mM extracellular NMN, corresponding to approximately 0.43 g/L, after 96 h of shake-flask cultivation in basal salt medium containing glucose and L-aspartate. The authors conclude that NMN biosynthesis in engineered P. putida KT2440 is feasible and stress balancing precursor supply, competing reactions and product transport. They present KT2440 as an alternative chassis for further pathway balancing and process optimization toward fermentative NMN production.
Supporting source [1]
How to interpret this
This explainer is based only on the abstract; the full text was not reviewed. Results come from shake-flask cultivation of engineered bacteria, not from human or animal studies, and the authors describe the work as a feasibility step toward further optimization.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Gao L, Wei L, Wang S, Li J, Liu J, Guo Z, Li ZM, Li Z. · europepmc.org · August 24, 2026