Lipase extraction from Aspergillus niger fermentation broth using aqueous two-phase partitioning

Purification of a desired protein from fermentation broth containing a wide variety of biomolecules is one of the major challenges in the biotechnology industry. The aim of this work was partitioning of lipase using aqueous two phase systems (ATPS). ATPS has proved to be a valuable tool for separating and purifying mixtures of biomolecules. In this study, the various aqueous two phase systems containing poly ethylene glycol 4000, 8000 and potassium oxalate and sodium-potassium tartrate were examined for extraction of lipase from fermentation broth. The results show that, the best operating system was contained the 17.5%(w/w) PEG4000,19.5%(w/w) potassium oxalate, 10.2%(w/w) crude fermentation broth loading and pH=5, resulted in partition coefficient (Ke) of 1.29, enzyme activity recovery of 84.93%, purification factor of 17.59 and specific activity of 22.22.