SEPARATION OF PROTEINS WITH REVERSE MICELLAR LIQUID MEMBRANES

Reverse micellar bulk liquid membrane was successfully applied to the separation of proteins with high selectivity by utilizing electrostatic interaction and/or steric interaction (size exclusion effect) between micelles and proteins. Highly selective uphill transport of proteins through the liquid membrane from one aqueous phase to another can be achieved by manipulating pH, concentration of KCl in both aqueous phases and initial water content in the membrane phase and also by selecting an anionic or cationic surfactant (AOT or CTAB). This is effected by the differences in the physical properties of the proteins to be separated such as isoelectric point, surface charge and molecular weight. Denaturation of proteins, mainly caused by complex formation with AOT molecules at low concentration of KCl in the aqueous phase for recovery, is small compared with that encountered in conventional batch extraction. The liquid-membrane separation system was further extended to the separation method utilizing the difference of transfer rate of proteins concerned. The combined liquid-membrane system with both AOT and CTAB membranes is also effective for the simultaneous separation of proteins. © 1990, The Society of Chemical Engineers, Japan. All rights reserved.