Poly(vinyl alcohol) Ultrafiltration Membranes: Synthesis,Characterization, the Use for Enzyme Immobilization

An enzymatic hydrolysis in a symmetric membrane, combining reaction and separation, has been studied. PVA hydrogel was chosen because of its hydrophilicity expecting to minimize membrane fouling and concentration polarization. The membrane pores containing covalently bound enzymes serve as catalyst support. The membrane immobilization of the enzyme and the filtration mode of operating the process were chosen in order to avoid product inhibition of the enzyme. The properties of cross‐linked PVA hydrogel were investigated. The conversion of the hydrolysis of p‐nitrophenyllaurate with two different loadings of Cr lipase was evaluated. The conversion of the reaction decreased with both increasing substrate flux and initial concentration. The kinetic parameters were obtained. Compared to the free lipase, the K_m of the membrane bonded enzyme was lower and its R_max approximately the same.