Enhancement Strategy for Protocatechuic Acid Production Using Corynebacterium glutamicum with Focus on Continuous...

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• Protocatechuic acid (PCA) is a valuable phenolic acid with diverse biological functions.
• Microbial synthesis offers a sustainable and efficient alternative to plant extraction for PCA production.
• High yields and energy savings are key advantages of microbial PCA synthesis.

Purpose of the Study:

• To optimize the production medium for enhanced PCA yield in Corynebacterium glutamicum.
• To investigate and mitigate PCA cytotoxicity during fermentation.
• To establish a continuous fermentation process for sustained PCA production.

Main Methods:

• Statistical optimization including full factorial design, steepest ascent, and response surface methodology.
• Batch and continuous fermentation strategies were employed.
• Cytotoxicity analysis of PCA on C. glutamicum growth and production.

Main Results:

• Optimized medium significantly increased PCA production to over 5 g/L in 72 h batch culture.
• PCA demonstrated cytotoxicity at approximately 5 g/L, inhibiting strain growth.
• Continuous fermentation sustained PCA production for 150 h by maintaining sub-inhibitory concentrations.

Conclusions:

• Statistical optimization effectively enhanced PCA production in C. glutamicum.
• Managing PCA cytotoxicity is crucial for high-yield microbial production.
• The developed methods pave the way for industrial-scale PCA manufacturing.