Fuente: WIPO "tomato" The present invention is in the technical field of synthetic biology, metabolic engineering and cell cultivation. The present invention relates to a de novo designed enzyme having alpha-1, 4- fucosyltransferase activity on the N-acetylglucosamine (GIcNAc) residue of Gal-β1,3-GlcNAc (lacto-N- biose, LNB), wherein said LNB resides in free form and/or is part of a saccharide. The present invention also relates to a de novo designed enzyme having alpha-1, 3-fucosyltransferase activity on the glucose (Glc) residue of Gal-β1,4-Glc (lactose). The present invention further relates to methods for the production of a fucosylated compound comprising Gal-β1,3-[Fuc-al,4]-GlcNAc and/or for the production of 3-fucosyllactose (3-FL, Gal-β1,4-[Fuc-al,3]-Glc). The present invention also provides a cell for expression of a de novo designed enzyme having alpha-1, 4-fucosyltransferase activity on the GIcNAc residue of LNB, wherein said LNB resides in free form and/or is part of a saccharide. The present invention also provides a cell for expression of a de novo designed enzyme having alpha-1, 3-fucosyltransferase activity on the Glc residue of lactose. The present invention further relates to a cell for production of a fucosylated compound comprising Gal-β1,3-[Fuc-al,4]-GlcNAc. The present invention further relates to a cell for production of 3-FL. The present invention also relates to the use of said cells in a cultivation or incubation.