Genetic Selection for Small Molecule Production in Competitive Microfluidic Droplets.

Area of Science:

• Synthetic biology
• Metabolic engineering
• Microbial biotechnology

Background:

• Biosensors are crucial for screening microbial production but are prone to false positives due to mutations.
• Existing methods physically separate biosensors and production pathways, limiting their use to screening, not selection.
• Novel strategies are needed to improve the accuracy and efficiency of selecting engineered microbes for small molecule production.

Purpose of the Study:

• To develop a novel biosensor-mediated selection strategy using bacterial competition.
• To address the challenge of false positives in biosensor-based selection systems.
• To enable efficient selection of engineered microbes for enhanced small molecule biosynthesis.

Main Methods:

• Developed a competitive co-culture system using engineered bacteria.
• Applied the strategy to the biosynthesis of cis,cis-muconate.
• Utilized microfluidic droplets to encapsulate and enrich producer strains.

Main Results:

• The novel selection strategy demonstrated a selective advantage for muconate-producing strains.
• The method successfully enriched producer strains from a mixed population.
• Microfluidic encapsulation improved the efficiency of selection in competitive co-cultures.

Conclusions:

• Biosensor-mediated bacterial competition offers a robust method for selecting small molecule production in engineered microbes.
• This approach effectively overcomes limitations of traditional biosensor systems, enabling selection rather than just screening.
• The strategy enhances microbial strain optimization and accelerates the development of novel metabolic pathways.