Efficient production of ectoine from Jerusalem artichoke using engineered Escherichia coli

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• Ectoine is a valuable osmoprotectant with applications in cosmetics and medicine.
• Jerusalem artichoke inulin is an underutilized, abundant carbohydrate source.
• Efficient microbial production of ectoine from non-food biomass remains a challenge.

Purpose of the Study:

• To engineer a recombinant Escherichia coli strain for enhanced ectoine production from Jerusalem artichoke inulin.
• To optimize metabolic pathways for improved substrate utilization and ectoine biosynthesis.
• To develop a cost-effective, non-food fermentation process for high-value ectoine production.

Main Methods:

• Modular pathway engineering of Escherichia coli, including promoter optimization and gene integration.
• Optimization of inulin hydrolase expression and downstream metabolic modules (fructose transport, glycolysis, oxaloacetate supply).
• Fermentation optimization using raw inulin extract and monosodium glutamate residue.

Main Results:

• Engineered strain ETC16 co-expressing gapA, ppc, and fruK with ΔiclR produced 6.51 g/L ectoine (0.13 g/g inulin).
• Optimized fermentation using raw inulin and MSG residue achieved 35.60 g/L ectoine (0.36 g/g inulin) in a 7.5 L fermenter.
• Demonstrated significant improvements in ectoine yield and substrate conversion efficiency.

Conclusions:

• Successful engineering of Escherichia coli for efficient ectoine production from Jerusalem artichoke inulin.
• Established a viable non-food fermentation strategy for producing high-value ectoine.
• Highlights the potential of utilizing agricultural byproducts for sustainable bioproduction.