Atividade e estabilidade operacional de lipase imobilizada em fosfato de zircônio na ausência e presença de polietilenoglicol

Abstract

Activity and operational stability of the immobilized lipase on zirconium phosphate in the absence and presence of polyethylene glycol. In the present work, different immobilization procedures were evaluated: direct addition of the lipase on zirconium phosphate (ZrP), and simultaneous addition of lipase and stabilizing agent (polyethylene glycol, MM-1500) on the same support. The selection of this additive was based on its compatibility with the lipase from Candida rugosa according to data previously obtained using controlled pore silica as support. The methodology of lipase immobilization on ZrP in the presence of PEG-1500 supplied more active immobilized derivatives (310.6 U mg-1 ) when compared with those obtained without addition of PEG- 1500 (162.8 U mg-1 ), providing high activity recovery in the immobilization step (88.7%). Better performance of the immobilized derivative prepared in the presence of PEG was also verified in organic medium (synthesis of butyl butyrate), in terms of activity and operational stability. These results can be attributed to the enzyme coated by the additive that probably increased the access of the substrate to the active site of the lipase