Engineering genetic circuits for dynamic control of central metabolism

Area of Science:

• Synthetic biology
• Metabolic engineering
• Microbial biotechnology

Background:

• Genetic regulation tools are crucial for controlling biosynthesis in microbial cell factories.
• Existing tools are often pathway-specific, limiting broad synthetic biology applications.
• Balancing metabolic flux for growth and production is underexplored.

Purpose of the Study:

• To establish a central metabolism-responsive biosensor system for dynamic metabolic flux regulation.
• To investigate the potential of such systems in enhancing compound biosynthesis.
• To address the limitations of pathway-specific genetic tools.

Main Methods:

• Development and characterization of the PdhR biosensor system responding to pyruvate.
• Screening of PdhR homologs and computational analysis for optimization.
• Site-directed mutagenesis to improve biosensor properties.
• Application of the biosensor for improving trehalose and 4-hydroxycoumarin (4HC) biosynthesis.

Main Results:

• The PdhR biosensor system was successfully established and characterized.
• Optimized biosensor properties through computational analysis and mutagenesis.
• Achieved a 2.33-fold increase in trehalose titer (3.72 g/L).
• Improved 4HC titer by 1.63-fold (491.5 mg/L) compared to static methods.

Conclusions:

• Dynamic metabolic flux distribution is essential for efficient biosynthesis.
• The PdhR biosensor system demonstrates broad applicability for central metabolism-derived compounds.
• This approach offers a versatile tool for synthetic biology and metabolic engineering.