Lipase immobilization on Polysulfone globules and their performances in olive oil hydrolysis

We prepared Polysulfone (PS) globules by pouring the PS solution droplets in to the non-solvent water. PS solutions (10, 15, and 20% (w/v), concentrations) of different viscosities resulted different physical appearances in globules. The lipase immobilizing amount (4.32 mg/g) was maximum for PS 20% globules as it possessed maximum BET pore surface area. The olive oil hydrolytic reaction parameters were fitted into the Lineweaver–Burk plot. The Km (apparent) values of all the immobilized globules were higher (83.3 mM) with respect to free lipases (62.5 mM) where as Vmax (apparent) values followed the reverse trend (129.8 U/mg for 20% and 120.5 U/mg for both 15% and 10% PS immobilized globules and 153.8 U/mg for the free lipase respectively). The hydrolytic activity to olive oil was decreased (∼16–20%) after five cycles.