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 K(m) (apparent) values of all the immobilized globules were higher (83.3mM) with respect to free lipases (62.5mM) where as V(max) (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 ( approximately 16-20%) after five cycles.