Colloidal gas aphrons generated from the anionic surfactant AOT for the separation of proteins from aqueous solution

Colloidal gas aphrons are microbubbles 10–100 μm in diameter created by intense stirring of a surfactant solution. They are composed of a gaseous inner core surrounded by a surfactant film. They have a high surface area, are relatively stable and have the ability to interact with proteins through electrostatic interactions. These characteristics make colloidal gas aphrons ideally suited for use as a downstream processing technique. In this study the effect of different process parameters on the recovery of three proteins (conalbumin, ribonuclease A and α-chymotrypsinogen A) was studied for a protein–AOT (sodium bis-(2 ethylhexyl) sulfosuccinate) system. High enrichment ratios (up to 8) and high recovery of the protein (85%) are found under optimum conditions.