Extraction of macromolecules in aqueous two-phase systems based on crude galactomannans and its derivatives

摘要

Aqueous two-phase systems have found use in biochemical research lor theseparation and purification of macromolecules, cells and cell fragments. In order tominimize the cost of two-phase systems based on purified polymers (such asfractionated dextran and Reppal PES), new aqueous two-phase systems, formed bycrude polymers, haVe been introduced. In this work, partition properties ofmacromolecules in poly(ethylene glycol) I locust bean gum; guar gum or derivatisedguar gum are reported. The effect of poly(ethlylene glycol) molecular weight, ionicstrength, affinity ligands, pH and temperature on partition behaviour and phasediagram is identical in this systems and in traditional poly(ethylene glycol) I dextranarid poly( ethylene glycol) I Reppal PES. Its application for enzyme affinity extraction isinvestigated. Two-phase systems based on such crude polymers may have"thedrawback of their degree of purification, which may interfere with the separationprocedure. However, this should not prevent its successful use in aqueous two-phasepolymer extractions. Results clearly indicate that these systems are an interestingalternative to conventional extraction systems.