An Engineered Variant of E. coli Nissle 1917 with Enhanced Transformation Efficiency and Robustness

Area of Science:

• Microbiology
• Synthetic Biology
• Gut Microbiome Research

Background:

• The gut microbiome significantly impacts human health, driving interest in its therapeutic potential.
• Bacterial chassis, like *E. coli* Nissle 1917 (EcN), are explored for drug delivery within the gut.
• EcN's utility is limited by its low transformation efficiency.

Purpose of the Study:

• To enhance the transformation efficiency of *E. coli* Nissle 1917 (EcN).
• To characterize the resulting strain for its suitability in gut therapeutic applications.
• To identify genetic mechanisms underlying the improved phenotype.

Main Methods:

• Adaptive laboratory evolution involving repeated cycles of electroporation and recovery.
• Comprehensive characterization of the evolved strain, including growth, permeability, motility, and iron competition.
• Genome sequencing and gene ontology enrichment analysis.

Main Results:

• The evolved EcN strain exhibited significantly improved transformation efficiency.
• The strain maintained key biological functions and showed enhanced robustness under gut-mimicking conditions.
• Genetic analysis revealed affected pathways potentially responsible for the enhanced phenotype.

Conclusions:

• Adaptive laboratory evolution is an effective strategy to improve EcN's transformation efficiency.
• The enhanced EcN strain is a more robust and efficient chassis for gut microbiome-based therapeutics.
• Understanding the genetic basis provides insights for further strain engineering.