The Study On Preparing Immunoglobulin G From Bovine Colostrum By Ultrafiltration

In the experiment ,Immunoglobulin-G was concentrated and separated from colostrum whey using hollow fibre ultrafiltrator (100ku MW cut-off).Concentrate times,selectivity and recovery ratio of IgG were investigated and the operating parameters such as running time,solution concentration,temperature,pressure,pH were also systematically studied.The relationship between the membrane running time and the permeate flux was studied in this article.The result shows that permeate flux is gradually decreasing with the running time extending.About 30 minutes later,the flux remains stable.The result of the effect of concentration on the flux shows that the permeate flux is decreasing with the solute concentration increasing.System hydrodynamics also has an effect on the permeate flux.The result shows that the effect of the operating pressure on the flux can be devided into three phase.When the transmembrane pressure is low( A P0. 02-0. 06MPa), the flux is increasing almost linearly with the pressure increasing.When the operating pressure continues ennancing,the flux also increases,but the increasing speed declines.In the third phase,the flux doesn't depend on the pressure increase.The above phenomenon dues to the formation of concentration polarization. Severe concentration polarization leads to gel layer formation.During the process of preparing IgG from the bovine colostrum whey,the effect of the temperature is complex.The result shows permeate flux becomes higher when the temperature increases.But if all the factors are taken into consideration,the optimum temperature is 20C ~30 C.pH play a critical roles in whey protein fractionation. pH affect the protein-protein and protein-membrane interactions.So the effect of pH is also complicated.The result in this experiment indicates at pH3.6 the permeate flux is the highest.Under the optimization of operating parameters,immunoglobulin-G was extracting from colostrum whey using hollow fibre ultrafiltrator (100ku MW cut-off).Selectivity is above 95% and the throughput of IgG is above 90%.The results demonstrate UF is a promising techique for fractionation of proteins.Operated at suitable operating conditions,UF can achieve complete seperation.This processing technology for IgG concentration and seperation can be scaled up.