Ionic liquid-cellulose film for enzyme immobilization

β-Galactosidase was immobilized in an ionic liquid-cellulose film that presents properties as increased flexibility and formability. A polyamine was added during the preparation of the film and their presence was detected by infrared analysis. Glutaraldehyde was used to activate the films in order to generate conditions for enzyme immobilization that preserved 60% of the initial β-galactosidase activity. The Michaelis-Menten kinetics parameters, Km and Vm, for immobilized enzyme were estimated to be 11.22 mM of ONPG and 460.83 μmol of ONP min−1 mg−1 enzyme, respectively and no marked shifts in optimum pH and temperature were observed after immobilization. Highly efficient lactose conversion was achieved in a batch process at 7 °C and 35 °C and was possible to reuse the new immobilized enzyme in 16 repeated cycles, at low temperature, without any drastic decrease in enzyme activity.