From glucose to gourmet: engineered bacteria churn out key food additive

The industrial production of inosinic acid (IMP), a popular umami enhancer in food industry, is constrained by major challenges. Chemical synthesis raises serious environmental concerns whereas enzymatic synthesis and RNA degradation rely on costly substrates. Moreover, reliance on non-classical industrial model organisms and low yields limited its availability.

Researchers used the model organism E. coli as the chassis to produce IMP. By reprogramming the metabolic flux network of E. coli and introducing amino acid mutations in the key enzymes in the synthesis pathway, the yield of IMP was significantly increased to 562.0 mg/L.

Engineered strain demonstrated a 4.77-fold higher IMP titer compared to the wild-type strain in shake-flask cultivation, and exhibited a 7.05-fold enhancement in bioreactor fermentation. Molecular modifications are expected to further enhance the performance of this strain in the IMP biosynthesis process. It provided valuable insights into microbial cell factories for the industrial production of umami enhancer.

The work entitled “Metabolic engineering of Escherichia coli for biosynthesis of inosinic acid” was published on Systems Microbiology and Biomanufacturing (published on August 18, 2025).