The present invention relates to an enzyme-catalyzed process for producing GDP- fucose from low-cost substrates guanosine and L-fucose or guanosine and D-Mannose in a single reaction mixture. Said process can be operated (semi)continuously or in batch mode. Further, said process can be adapted to produce fucosylated molecules and biomolecules including glycans, such as human milk oligosaccharides, proteins, peptides, glycoproteins or glycopeptides.

The present invention relates to an enzyme-catalyzed process for producing GDP-fucose from low-cost substrates guanosine and L-fucose or guanosine and D-Mannose in a single reaction mixture. Said process can be operated (semi)continuously or in batch mode. Further, said process can be adapted to produce fucosylated molecules and biomolecules including glycans, such as human milk oligosaccharides, proteins, peptides, glycoproteins or glycopeptides.