EXTRACTION OF ENZYMES BY REVERSE MICELLES

Liquid-liquid extraction by reverse micelles of ionic surfactants in organic solvents is well suitable for separation and purification of extracellular enzymes from complex fermentation media, as demonstrated with alpha-amylase from Bacillus licheniformis (activity yield: 89%, purification factor: 8.9). The partitioning behaviour of the enzyme in the Winsor-2 system corresponds to results obtained with a synthetic aqueous phase of equivalent ionic strength; medium components like biomass, proteins, etc. have no specific influence. Using various cationic surfactants (TOMAC, BDBAC, CTAB, CPB, CPC) the influence of the surfactant, the organic solvent and additive inorganic electrolytes on the partitioning behaviour of proteins in Winsor-2 systems is discussed. The partition coefficient depends on six parameters: surfactant charge, protein size and titration behaviour, aqueous-phase pH and ionic strength, and water content/size of the reverse micelles.