Desenvolvimento de membranas de afinidade para a separação de bromelina

Abstract

There is a great deal of interest in protein separation and concentration processes, as purification steps correspond to 70-90% of total production costs. Bromelain is an enzyme that can be obtained from pineapple, including its parts considered as residues and has high commercial value. The membrane separation processes appears as an attractive method, as is the case of affinity membranes, which combine high selectivity with high productivity associated with filtration membranes. However, despite these advantages, little has been studied regarding the application of this membrane in the separation of bromelain. The objective of this work was to produce porous affinity membranes through the surface modification of commercial polycarbonate membrane and to produce dense affinity membranes by surface modification of dense polyvinyl alcohol (PVA) membranes synthesized in laboratory. Both were applied in the separation of bromelain and bovine serum albumin (BSA), model protein. For this, the parameters for the development of these membranes, such as PVA drying temperature, glutaraldehyde concentration (GA), adsorbent immobilization temperature (Coomassie blue brilliant), as well as the adsorption and desorption processes were investigated. The results of hydraulic permeability and adsorption of BSA gave evidence of surface modification, showing that the proposed route has potential to be used in the development of affinity membranes. In the case of BSA, it was possible to prove that the surface modification increased the adsorption of this protein by 76% in the dense membrane, with 76% desorption. In the porous membrane in a continuous system, it was possible to adsorb 67.71 mg of BSA per gram of membrane. In the case of bromelain at pH 6.5, 61.07 mg of bromelain per gram of porous membrane was obtained and 6% of it was desorbed on a dense membrane with an expressive increase in specific enzyme activity from 76.7 to 989.1 U / mg.