Isolation and purification of protease from human placenta by foam fractionation

The effect of operating parameters like pH, protein concentration, column geometry, and gas flow rate on the separation efficiency of proteolytic enzymes from crude human placental homogenate has been studied in a batch foam column. Purification has been found to be optimum at pH 8.0, close to the isoelectric pH, at which the surface adsorption of the protein on the foam bubbles is maximum. Both purification and recovery varied significantly with total protein concentration. Stable bubble formation was hindered at lower protein concentrations, while extraneous proteins rather than the protease were preferentially adsorbed at higher protein concentrations, decreasing the purification efficiency. Column diameter and column height should be optimized for any specific feed protein concentration and gas flow rate. However, the enrichment ratio was found to decrease with the increase in flow rate. The results indicate that foam fractionation is an effective separation process for recovering valuable biochemicals from biological materials.