Effect of pH, ion type and ionic strength on partitioning of proteins in reverse micelle systems

Optimization of AOT reversed micelle forward extraction of 7S globulin subunits from soybean proteins

The work attempted to study on separating the α', α and β subunits of 7S globulin from soybean proteins by reverse micelles. The effects of six single factors (W0, time, temperature, pH, surfactant concentration and salt solution species) on three subunit partitioning were discussed. The main influence factors (time, temperature and surfactant concentration) were optimized by the response surface test (Box-Behnken design, three factor three level) in order to optimize the forward extracting three subunits of 7S globulin. It was observed that the independent factor had substantial effect on the forward extraction yield of three subunits of 7S globulin. The statistical analysis showed that the reverse micelles could significantly affect the forward extraction efficiency of protein subunits. The highest forward extraction efficiency of α', α and β subunits achieved 78.21, 63.65 and 61.34%, respectively. The proposed method also showed that the forward extraction efficiency of subunits with larger molecular weight was higher than low molecular weight.

Effect of CO(2) and CHF(3) on the Solubilization of Protein in Reverse Micelles

The effect of dissolved CO(2) and CHF(3) on the precipitation of bovine serum albumin (BSA) from reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in 2,2,4-trimethylpentane (iso-octane) has been studied at 308.15 K. It was found that BSA can be precipitated completely by CO(2) while the AOT and water remain in the iso-octane continuous phase. This opens up a possibility for recovery of protein solids directly from reverse micellar solutions. CHF(3) is also an effective agent for precipitation of BSA in the reverse micelles when the expansion coefficient of CHF(3) exceeds 0.4. However, the condition required for complete removal of the BSA using CHF(3) results in some precipitation of AOT and water from the solution. Copyright 2000 Academic Press.