Production of Colanic Acid Hydrolysate and Its Use in the Production of Fucosylated Oligosaccharides by Engineered Saccharomyces Cerevisiae

Fucose is a rare sugar obtained from fucoidan in brown algae. However, fucoidan contains low amounts of fucose, making the process of obtaining fucose inefficient and expensive. Colanic acid (CA) is a capsular exopolysaccharide produced by Escherichia coli, which has great potential as a source of fucose owing to its high proportion of fucose. In this study, we aimed to efficiently obtain fucose from the hydrolysis of CA and then produce 2'-fucosyllactose (2'-FL) and 2' -fucosylgalactose (2' -FG) using fucose in the CA hydrolysate, using engineered yeast. For the acid hydrolysis of CA, optimal conditions were 110 degrees C, 4% (w/v) H3PO4, and 60 min. Using fucose from CA hydrolysate as a substrate, 2'-FL and 2' -FG were produced from engineered Saccharomyces cerevisiae. This is the first report of producing fucosylated oligosaccharides from CA. Considering the benefits of CA in obtaining fucose, these results can lead to further applications of CA as a fucose supplier.