L‐Fucose production by engineered Escherichia coli

Abstract L ‐Fucose (6‐deoxy‐ L ‐galactose) is a major constituent of glycans and glycolipids in mammals. Fucosylation of glycans can confer unique functional properties and may be an economical way to manufacture L ‐fucose. Research can extract L ‐fucose directly from brown algae, or by enzymatic hydrolysis of L ‐fucose‐rich microbial exopolysaccharides. However, these L ‐fucose production methods are not economical or scalable for various applications. We engineered an Escherichia coli strain to produce L ‐fucose. Specifically, we modified the strain genome to eliminate endogenous L ‐fucose and lactose metabolism, produce 2′‐fucosyllactose (2′‐FL), and to liberate L ‐fucose from 2′‐FL. This E. coli strain produced 16.7 g/L of L ‐fucose with productivity of 0.1 g·L −1 ·h −1 in a fed‐batch fermentation. This study presents an efficient one‐pot biosynthesis strategy to produce a monomeric form of L ‐fucose by microbial fermentation, making large‐scale industrial production of L ‐fucose feasible.