Studies On The Separation And Purification And Biological Activity Of Colostrum Lactoferrin

Lactoferrin is an active protein, which is twice from the colostrum through the ammonium sulfate precipitation, organic solvents and ethanol precipitation of the crude product further purified by gel chromatography and obtained. Lactoferrin is already proven with a variety of biological functions:Increased iron absorption of intestinal cells, antibacterial, antiviral, antioxidant, anticancer, regulate the immune reaction. And has been widely used in food, livestock, etc. Current domestic and international research on the presence of lactoferrin common problem is that a variety of separation and purification methods used in the cost is too high, so many studies can only be confined to laboratory scale, difficult to achieve industrial production.This experiment were optimized its crude and purification conditions and studied their ability of broad-spectrum antimicrobial and antioxidant capacity.1 Study of the optimization crude of lactoferrin, lactoferrin was crude extracted by salt-out and organic reagent precipitation from bovine colostrums, and the optimal isolating conditions were obtained by single factor and orthogonal experiments, which were:salt-out at pH8.5 with 80%(NH4)2SO4, precipitation with 60% ethanol. The result from SDS-PAGE showed that the purity of the lactoferrin was 48%, and the molecular weight was about 80600Da.2 Study of the purification of tactoferrin, gel chromatography to get the crude and purified samples of lactoferrin, a single factor and orthogonal test method factors influencing the effect of purification were studied, the results show that:elution time of 1h, sampling volume 7mL, the flow rate of 0.8mL/min, buffer pH value of 7.6 obtained under the conditions lactoferrin purity of the samples up to 93%, molecular weight of about 80200Da.3 Study of the ability of broad-spectrum antimicrobial of lactoferrin, by measuring the size of inhibition zone, the initial known bovine lactoferrin against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella and Pasteurella have some antibacterial effects; then the minimum inhibitory concentration by determination of known:milk ferritin from Staphylococcus aureus in the MIC for the 1500μg/mL, E. coli MIC for the 2000μg/mL, Salmonella and Pasteurella the MIC for the 1250μg/mL, on Bacillus subtilis of the MIC was 1500μg/mL. 4 Study of the antioxidant capacity of lactoferrin, purification of crude by lactoferrin after the total antioxidant capacity, hydroxyl radical scavenging, superoxide radical scavenging ability, results show that:the lactoferrin has a strong total antioxidant capacity, hydroxyl radical scavenging, superoxide scavenging. Lactoferrin concentration in 2～6 mg/mL range, the total antioxidant capacity, and superoxide radical scavenging capacity with the increase of sample concentration; but its concentration in the 6～10mg/mL range, with the sample concentration increases, the total antioxidant capacity, hydroxyl radical scavenging, superoxide radical scavenging rate did not change significantly.