High-speed protein purification by adsorptive cation-exchange hollow-fiber cartridges

Novel cation-exchange adsorptive membranes were assessed according to their protein adsorption capacity and permeation flowrate. Maximum static adsorption capacities for the three main egg-white proteins, lysozyme, ovoalbumin and conalbumin, were 140, 88 and 66 mg/ml, respectively. However, membranes showed an inverse relationship between permeation flowrate and static protein adsorption capacity. Two size cartridges (membrane volume of 0.42 and 3.5 ml) were built using the selected membrane. An adsorptive cross-flow cartridge was tested to recover and purify lysozyme from an egg-white solution. Breakthrough curves developed using a pure lysozyme solution showed a dynamic-to-static capacity ratio of 0.6, which was reduced to 0.4 during lysozyme recovery from egg-white solution in cross-flow mode. Total process cycle for the enzyme recovery and purification was in the range of 10–15 min for both cartridges. In both cases high-purity lysozyme (95%) was recovered with a productivity of 150 g/(l h) and no size-exclusion effect was detected.