Glycans, composed of linked monosaccharides, play crucial
roles
in biology and find diverse applications. Enhancing their enzymatic
synthesis can be achieved by immobilizing enzymes on materials such
as microgels. Here, we present microgels with immobilized glycosyltransferases,
synthesized through droplet microfluidics, immobilizing enzymes either
via encapsulation or postattachment. SpyTag-SpyCatcher interaction
was used for enzyme binding, among others. Fluorescamine and permeability
assays confirmed enzyme immobilization and microgel porosity, while
enzymatic activities were determined using HPLC. The potential application
of microgels in cascade reactions involving multiple enzymes was demonstrated
by combining β4GalT and α3GalT in an enzymatic reaction
with high yields. Moreover, a cascade of β4GalT and β3GlcNAcT
was successfully implemented. These results pave the way toward a
modular membrane bioreactor for automated glycan synthesis containing
the presented biocatalytic microgels.