Partitioning of pequi seed (Caryocar brasiliense Camb.) lipase in aqueous two-phase systems composed of PEG/2-propanol + ammonium sulfate + water

Lipases (E.C. 3.1.1.3) are biological catalysts widely used in industry due to their versatility, selectivity and specificity. For this reason, the interest in their purification has shown great potential. A technique employed in enzymes recovery capable of preserving their biological activity is partitioning using aqueous two-phase systems. Therefore, the objective of this work was to evaluate the partitioning of lipase extracted from pequi seed in aqueous two-phase systems composed of PEG 4000 or 2-propanol with ammonium sulfate and water at 298 K and 308 K. Lipase partitioning in aqueous two-phase systems was statistically analyzed using the F test and comparison of means test, showing a significant effect (P < 0.05) for the interaction between temperature and type of system, as well as the mutual influence of both parameters on each other in the response variables (protein partition coefficient, enzyme partition coefficient, enzyme recovery, selectivity and purification factor). It was verified that the enzyme had a preference for the salt-rich phase (bottom phase) and that the ATPS composed of 2-propanol and ammonium sulfate with crude extract samples at 298 K obtained the best partition results (yield of 86.39%, selectivity of 0.057 and purification factor of 4.48) under the experimental conditions.