Cell-wall engineering of living bacteria

Area of Science:

• Microbiology
• Synthetic Chemistry
• Biotechnology

Background:

• Bacterial cell wall synthesis is a crucial target for antimicrobial development.
• Modifying bacterial cell walls can enable new biotechnological applications.
• Existing methods for bacterial cell wall modification are limited.

Purpose of the Study:

• To develop a method for chemically modifying living bacterial cell walls.
• To synthesize and incorporate modified cell-wall precursors into bacteria.
• To create a platform for attaching molecules to bacterial surfaces.

Main Methods:

• Synthesized UDP-MurNAc pentapeptide, lipid I, and lipid II derivatives.
• Attached fluorescein or a ketone group to the UDP-MurNAc pentapeptide.
• Incorporated modified precursors into Gram-positive and Gram-negative bacteria, using EDTA treatment for Gram-negative bacteria.

Main Results:

• Fluorescein-labeled UDP-MurNAc pentapeptide was successfully incorporated into both Gram-positive and Gram-negative bacteria.
• EDTA treatment enhanced precursor incorporation into Gram-negative bacteria (e.g., Escherichia coli) by increasing outer membrane permeability.
• Ketone-modified UDP-MurNAc pentapeptide was incorporated into lactic acid bacteria, providing a functional handle for attaching larger molecules.

Conclusions:

• Chemical modification of bacterial cell walls using synthesized precursors is feasible.
• This approach allows for the targeted delivery of functional molecules to bacterial cell walls.
• The developed method offers a versatile platform for bacterial surface functionalization.