S. Jarudilokkul et Dc. Stuckey, Continuous forward and back extraction of lysozyme from egg white using reverse micelles, SEP SCI TEC, 36(4), 2001, pp. 657-669
Gentle mixing characteristics in a Graesser contactor can avoid the formati
on of stable emulsions, and this is one advantage of this contactor when us
ed with reversed micellar extractions. However, this characteristic of the
contactor is a disadvantage for back extraction using the conventional meth
od (extremes in pH and ionic strength) because it gives a low extraction yi
eld and requires a larger contactor. In order to develop an integrated proc
ess for continuous protein separation using reverse micelles, this work foc
used on assessing the novel technique of back extraction using a counterion
ic surfactant in a mixer-settler. It was found that the process gave a high
extraction yield (95-100%) within an extraction time of only 5 min. Lower
mixing speeds (200 rpm) and pHs (6) resulted in the highest sedimentation r
ate in the organic phase. Unfortunately, the cloudiness of the aqueous phas
e and the slow rate of lysozyme transfer into the aqueous phase in the sett
ler were potential drawbacks of the system. However, the use of centrifugal
force was found to be an important factor in enhancing the rate of back ex
traction when using a counterionic surfactant. Based on previous work of ou
rs on forward extraction in a Graesser contactor, the continuous separation
and recovery of proteins using reverse micelles seems feasible.