Single-step purification of peroxidases from rice bran: Evaluation of the main expanded-bed chromatography parameters

Abstract

Peroxidases catalyze the oxidation-reduction reactions of organic substrates and present several applications in the biotechnological, clinical, environmental, and industrial areas. Among the chromatographic strategies applied to peroxidase purification to allow future uses, expanded-bed adsorption (EBA) stands out due to the large volumes of purified enzyme and potential for scale-up. In this paper, the main EBA parameters were evaluated in the purification of rice bran peroxidases. Sodium acetate buffer (pH 4.5) and expansion degree of 2.5 were the most favorable conditions to the enzyme adsorption onto Streamline® SP resin, showing an enzymatic activity at equilibrium on the solid phase (q*) of 2.68 U/mL resin, a partition coefficient (f) of 38.35 and a dynamic binding capacity (Q10%) of 0.19 U/mL resin. Rice bran peroxidase was purified in 14.1-fold (± 1.3) with 49.8% (± 2.5) of recovery by using 25 mmol/L acetate buffer pH 5.5 in the washing step, and elution combining stepwise (0.15 mol/L NaCl) and linear gradient (0.15–1 mol/L NaCl), using acetate buffer pH 5.5 with 1 mmol/L of CaCl2. Based on the results obtained, EBA showed to be a viable single-step strategy for peroxidase purification.