Liquid-liquid extraction of a Schistosoma mansoni recombinant protein froman Escherichia coli extract in aqueous two-phase system

This work describes the partition of a Schistosoma mansoni tegumental antig en produced by a recombinant Escherichia coli strain using an aqueous two-p hase system composed of polyethylene glycol (PEG) and potassium phosphate. The effects of the polymer molecular weight, tie line length and pH on anti gen partitioning were investigated. The detection of the antigen in both ph ases were determined by ELISA. The system composed of PEG 3550 (19.7% w/w) and potassium phosphate (17.7% w/w) led to a yield of 59% and an antigen pu rification factor of 3 in the PEG-rich phase. It was observed that the anti gen partition in ATPS was strongly affected by the pH value and tie line le ngth. In addition, it was possible in a single step, to remove the cell deb ris, that precipitated at the interface of the system.