Isolation of lactoferrin from bovine colostrum by ultrafiltration coupled with strong cation exchange chromatography on a production scale

Lactoferrin (LF) was isolated from bovine colostrum by ultrafiltration and then purified with a fast flow strong cation exchange chromatography system in a production scale. A two-step ultrafiltration process was performed with membranes of nominal molecular weight cut-offs of 100 kDa for ultrafiltration (UF) step 1 (UF-1) and 10 kDa in the UF step 2 (UF-2). The UF-1 process was performed at fixed transmembrane pressure (TMP), tangential flow velocity and temperature equivalent to 200 kPa, 5 m/s, and 25 °C, respectively. The optimum operating parameters for the UF-2 were a tangential flow velocity of 4 m/s, limiting TMP of 150 kPa, and an operating temperature of 50 °C. The predicted permeate flux based on a resistance mathematical model was not significantly (p > 0.05) different from those of the actual experiment. The LF concentrated in the UF-2 retentate reached a purity of 30.88% (w/w) and a recovery of 94.04%. A stepwise procedure for purification of the crude LF was conducted using a preparative-scale strong cation exchange chromatography. The LF eluted with 1.0 M NaCl aqueous buffer showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a molecular weight of 80,400 Da. The purity and the recovery of the final LF product were 94.20% and 82.46%, respectively. The process developed in this work is a significant improvement over the commercial practice for the fractionation of LF from bovine colostrum.