Shikimate Metabolic Pathway Engineering in Corynebacterium glutamicum

Area of Science:

• Biotechnology
• Metabolic Engineering
• Synthetic Biology

Background:

• Shikimate is a crucial precursor for antiviral medications, including oseltamivir (Tamiflu).
• Traditional plant extraction for shikimate is costly and unreliable.
• Microbial production offers a sustainable alternative to plant-derived shikimate.

Purpose of the Study:

• To engineer a microbial cell factory for high-yield shikimate production.
• To optimize Corynebacterium glutamicum for efficient shikimate biosynthesis.
• To develop a robust fed-batch fermentation process for shikimate accumulation.

Main Methods:

• Disruption of the shikimate kinase gene (aroK) to prevent shikimate degradation.
• Sequential disruption of genes in the shikimate bypass route (QsuB, Pyk1, QsuD).
• Overexpression of key shikimate pathway genes (aroE, aroB, aroF, aroG) via an artificial operon.
• Optimization of fermentation medium and fed-batch conditions.

Main Results:

• Engineered C. glutamicum strain achieved significant shikimate overproduction.
• Achieved approximately 37.3 g/l of shikimate in a 7-L fed-batch fermentation.
• Demonstrated the effectiveness of rational cell factory design and process optimization.

Conclusions:

• Microbial production of shikimate is a viable and efficient alternative to plant extraction.
• Engineered C. glutamicum serves as a robust platform for shikimate biosynthesis.
• This approach supports the sustainable supply of shikimate for pharmaceutical applications.