In the perspective of designing effective hybrid chemical processes (i.e. combining reaction on immobilized enzymes and in situ separation through a membrane), it is essential to first master the step of enzyme immobilization on conventional polymeric membranes that are routinely employed industrially. Such supports differ from usual enzyme carriers such as porous silica, or resins beads (i.e. typically 100 µm particles, with average pore size of 20-60 nm 45 ), in the sense that polymeric membranes tend to display lower specific surface area available for immobilization , resulting in potentially lower enzyme loadings . Also, their surface is usually not directly amenable to enzyme grafting, so that chemical functionalization is needed. Thus, it is of prime importance to develop robust enzyme immobilization strategies on these membranes, with the aim to optimize enzyme loading, preserve specific activity of immobilized enzymes, and avoid leaching.