Overproduction of Native and Click-able Colanic Acid Slime from Engineered Escherichia coli

Area of Science:

• Microbiology
• Synthetic Biology
• Biochemistry

Background:

• Bacterial exopolysaccharides, like colanic acid from Escherichia sp., are gaining attention for their diverse applications.
• Current synthetic biology methods for producing colanic acid and its derivatives are limited.
• Colanic acid is the primary component of Escherichia sp. slime.

Purpose of the Study:

• To engineer Escherichia coli for enhanced production of colanic acid.
• To develop a method for functionalizing colanic acid with organic cargo.
• To explore the potential of molecular-engineered biopolymers in research.

Main Methods:

• Engineered a strain of Escherichia coli JM109 for colanic acid overproduction from d-glucose.
• Utilized a heterologous fucose salvage pathway from Bacteroides sp.
• Incorporated chemically synthesized l-fucose analogues with an azide motif into the slime layer.
• Employed click chemistry to attach organic cargo to the cell surface.

Main Results:

• Achieved overproduction of colanic acid up to 1.32 g/L.
• Successfully incorporated azide-modified l-fucose analogues into the bacterial slime layer.
• Demonstrated the attachment of organic cargo to the cell surface via click reaction.

Conclusions:

• The engineered Escherichia coli strain efficiently overproduces colanic acid.
• Metabolic incorporation of functionalized fucose analogues enables cell surface modification.
• This molecular-engineered biopolymer serves as a novel tool for chemical, biological, and materials research.