Purification of Endopolygalacturonase from Submerged Culture of Aspergillus awamori L1 Using a Two-step Procedure: Enzyme Precipitation and Gel Filtration

The purification of extracellular endopolygalacturonase (endo-PG) from the filtrate of Aspergillus awamori L1 submerged culture was carried out using a two-step procedure: enzyme precipitation by organic solvents, polymers or salts; and gel filtration using Sephadex G-75 column. The results show that ammonium sulfate was the suitable precipitant in the two-step procedure for endo-PG purification. Firstly, ammonium sulfate was added to the crude enzyme solution with the concentration of 47.2% (w/v) for endo-PG precipitation. The precipitates were then isolated and redissolved in a buffer solution to prepare for the gel filtration step. Consequently, the purification factor achieved 30.4-fold and the endo-PG recovery yield obtained 68.60% in comparison to the crude enzyme solution.