Purification of lactoferrin from sweet whey using ultrafiltration followed by expanded bed chromatography

Abstract

Lactoferrin is an important protein found in sweet whey that has several biological activities, such as nutritional, antimicrobial, antiviral, anti-inflammatory, antioxidant, anticarcinogenic and immunomodulation. However, it is found in very low concentration in whey and its capture and purification is a challenge. This study proposes a simple strategy in which two operations for the separation and purification of lactoferrin are integrated. Sweet whey containing 0.12 mg/mL of lactoferrin was subjected to microfiltration for clarification, followed by ultrafiltration and diafiltration in order to reduce in 10 times the total volume with simultaneous concentration and pre-purification of lactoferrin to 1.1 mg/mL. In the second operation, the protein was purified by a preparative chromatography based on cationic exchange expanded bed chromatography (EBC). Adsorption isotherms were determined which allowed establishing the conditions for the chromatographic step. Hydrodynamic studies of the expanded bed and its dynamic binding capacity were also accomplished. The final concentration of the purified lactoferrin was 17.4 mg/mL, resulting in a purity of 92.7% and recovery of 87.0%.