No abstract

In this work, foam fractionation (FF), a cost-effective method, was used to enhance the silica gel adsorption (SGA) of urokinase from human urine. The analysis of how FF enhanced the adsorption/desorption of urokinase onto silica gel was conducted. The results show that FF increased both the adsorption rate of urokinase onto silica gel and the activity concentration of urokinase adsorbed at silica gel by pre-enriching urokinase from urine. It also reduced the activity loss of urokinase in the desorption process. Then, a coupled technology of FF and SGA was developed. The effects of pH, superficial air flow rate, beta-cyclodextrin concentration, and amount of silica gel added on activity recovery yield and purification fold of urokinase were studied. At pH 7.5, superficial air flow rate 1.70 mm/s, beta-cyclodextrin concentration 0.2 g/L, and amount of silica gel added 0.9%, the activity recovery and purification fold of urokinase reached 89.5% and 56.8 in the coupled technology, which were 25.3% and 79.2% higher than those obtained by SGA alone, respectively. Furthermore, the amount of silica gel added in the coupled technology was 40.0% lower than that in SGA alone. Therefore, FF effectively enhanced the SGA of urokinase from human urine.