Isolation and purification of lactoferrin and immunoglobulin G from bovine colostrum with serial cation-anion exchange chromatography

High-value dairy proteins such as lactoferrin (LF) and immunoglobulin (IgG) were separated from bovine colostrum. The whey was initially adjusted to pH 6.8 with 1 mol/L NaOH and then went through centrifugation, precipitation, and filtration to eliminate the fat and caseins in bovine colostrum. The treated whey was further ultra-filtrated to partially remove both other proteins and carbohydrates under 50 kD molecular weight. Then the ultra-filtrated whey was passed through cation and anion exchange columns in series. The LF and IgG were adsorbed on cation and anion exchanger, respectively, due to their different pI. Both the cation and anion exchange columns were washed with de-ionized water followed by successive elution with sodium chloride solutions of increasing molarities (0.27 and 0.85 mol/L; 17 and 51 mmol/L) in a stepwise manner, respectively. After desalted, the elution was freeze-dried. Finally, the LF and IgG with respective purities of 95.0% and 96.6% were obtained.