2025/12/22 by Congqiang Zhang, Sudha Shukal · 1 voice
Biochemistry, Genetics and Molecular Biology · #Enzyme Catalysis and Immobilization #Microbial Metabolic Engineering and Bioproduction #Microbial metabolism and enzyme function
paper · doi:10.1021/acssynbio.5c00602
openalex created_date 2025/12/22 · openalex publication_date 2025/12/22 · openalex updated_date 2026/06/15
Precise control of gene expression is essential to synthetic biology and metabolic engineering, particularly for microbial production. The widely used IPTG-inducible T7lac promoter (P T7lac ) offers strong expression but suffers from metabolic burden, inclusion body formation, and induction heterogeneity. Conversely, the arabinose-inducible araBAD promoter (P BAD ) provides tight regulations but yields modest expression levels, is incompatible with glucose media, and requires high inducer concentrations (20–100 mM). We introduce the arabinose-inducible univariant control system (AUCS), a robust, tightly regulated, and low-cost expression platform designed to combine the strengths of P T7lac and P BAD while overcoming their drawbacks. AUCS eliminates carbon catabolite repression and minimizes induction heterogeneity via the constitutive expression of the arabinose transporter AraE. Disruption of the arabinose catabolism enables maximal protein output with only 3 μM l -arabinose, orders of magnitude lower than P T7lac and P BAD systems, achieving a >99% reduction in inducer cost. Leveraging a customized promoter library (P TA1–3 ), AUCS enables the precise, high-yield expression of single proteins, multienzyme operons, and complex biosynthetic pathways (>10 genes). Benchmarked against P T7lac, AUCS achieved comparable or superior yields of proteins (the egg-white protein ovalbumin), enzymes (terpene synthases, carotenoid cleavage dioxygenases), and secondary metabolites (linalool, nerolidol, and sclareol) while maintaining outstanding reproducibility and stability over 36 generations. AUCS represents a powerful advancement for precision fermentation, enabling sustainable and cost-effective production of high-value biomolecules and substantially reducing the environmental footprint of chemical manufacturing.