PURIFICATION PROCESS FOR BETA-GALACTOSIDA SE USING AQUEOUS 2-PHASE PARTITIONING AND PEG FRACTIONAL PRECIPITATION

Combining aqueous two-phase partitioning and PEG fractional precipitat ion, a simple and effective purification process for the target intra- cellular enzyme beta-galactosidase (beta-gal) from E. coli (W 3110) ce lls was developed based on the evaluated differences between surface p roperties of beta-gal and those of other total soluble proteins. beta- gal was partitioned to the PEG rich top phase of the used aqueous two -phase system and finally recovered at high selectivity and yield with the following PEG fractional precipitation mediated by the addition o f salt to the separated top phase.