Enhancing the efficiency of L-tyrosine by repeated batch fermentation

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• L-tyrosine is a crucial aromatic amino acid with growing industrial demand.
• Current L-tyrosine production methods require optimization for cost-effectiveness.
• Escherichia coli (E. coli) is a common host for amino acid fermentation.

Purpose of the Study:

• To improve the efficiency of L-tyrosine production using repeated batch fermentation.
• To determine optimal parameters for repeated batch fermentation of L-tyrosine.
• To achieve higher productivity and yield compared to conventional fed-batch fermentation.

Main Methods:

• Utilized E. coli GHLTYR-168 for L-tyrosine fermentation.
• Implemented repeated batch fermentation strategy, optimizing broth replacement time and ratio.
• Conducted fermentation over multiple batches to assess cumulative efficiency.

Main Results:

• The optimal broth replacement ratio for repeated batch fermentation was determined to be 70%.
• Repeated batch fermentation over 5 batches within 100 hours showed peak efficiency in the third batch.
• Achieved a productivity of 2.53 g/(L·h) and a yield of 30.1% in the third batch.
• Demonstrated a 43.8% increase in productivity and a 74.0% increase in yield compared to fed-batch fermentation.

Conclusions:

• Repeated batch fermentation is a highly effective strategy for significantly enhancing L-tyrosine production efficiency.
• The optimized repeated batch fermentation process achieved record levels of L-tyrosine fermentation.
• This method offers a more cost-effective and industrially viable approach for L-tyrosine manufacturing.