Food Science and Technology, Ferdowsi University of Mashhad
In this study, Aspergillus niger lipase after extraction of medium culture was precipitated with different percentages of acetone and purified by ion exchange chromatography using SP-sepharose HP and Q-sepharose HP. The process of purification of the anzyme was studied by electrophoresis and the molecular weight was detected and determined by Zymography using overlying containing phenol red and rhodamine B. The results show that the vast majority of lipase from this strain has been precipitated by acetone 70% saturation, and leads to the 1.67 fold the purified enzyme, with special activities 32.8 U/mg and 38.5%efficiency. Using two-phase chromatography, enzyme specific activity reached 246.47 U/mg and 12.59-fold purification were achieved. The results of Zymography and electrophoresis indicate a lipase band with weighing about 30 kDa.