methyl 8-{[beta-D-galactosyl-(1->3)-N-acetyl-beta-D-glucosamyl]oxy}nonanoate + GDP-beta-L-fucose = methyl 8-{[beta-D-galactosyl-(1->3)-[alpha-L-fucosyl-(1->4)]-N-acetyl-beta-D-glucosaminyl]oxy}nonanoate + GDP + H(+) — reaction