Metabolic flux reprogramming and protein engineering drive efficient l-arginine biosynthesis

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Biotechnology

Background:

• Industrial l-arginine production faces challenges in metabolic regulation, pathway engineering, and fermentation optimization.
• Efficient biosynthesis is crucial for food, feed, pharmaceutical, and cosmetic applications.

Purpose of the Study:

• To improve industrial-scale l-arginine biosynthesis through metabolic reprogramming and enzyme engineering.
• To identify key gene targets and optimize fermentation parameters for enhanced l-arginine production.

Main Methods:

• Utilized an enzyme-constrained model (ec_iML1515) to identify 11 gene targets.
• Performed metabolic reprogramming and engineered argininosuccinate synthetase (ArgG).
• Optimized fermentation temperature and pH for large-scale production.

Main Results:

• Developed strain Arg10 with an l-arginine titer of 87.24 g/L by rebalancing precursor pools.
• Engineered ArgG (Y131F/K132R) in strain Arg11, increasing titer to 94.80 g/L and reducing aspartate accumulation 7.6-fold.
• Achieved a final l-arginine titer of 114.18 g/L, yield of 0.57 g/g, and productivity of 2.27 g/L/h in a 3-m³ fermenter.

Conclusions:

• Successfully enhanced l-arginine production through integrated metabolic engineering and fermentation optimization.
• The engineered strain Arg11 and optimized process represent the best performance reported to date for l-arginine biosynthesis.
• This work provides a robust platform for the industrial production of l-arginine.