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

The fundamental biology and application of bacterial exopolysaccharides is gaining increasing attention. However, current synthetic biology efforts to produce the major component of Escherichia sp. slime, colanic acid, and functional derivatives thereof have been limited. Herein, we report the overproduction of colanic acid (up to 1.32 g/L) from d-glucose in an engineered strain of Escherichia coli JM109. Furthermore, we report that chemically synthesized l-fucose analogues containing an azide motif can be metabolically incorporated into the slime layer via a heterologous fucose salvage pathway from Bacteroides sp. and used in a click reaction to attach an organic cargo to the cell surface. This molecular-engineered biopolymer has potential as a new tool for use in chemical, biological, and materials research.