| abstract |
From a culture of E. coli the bacterial mass is flocculated by addition of an organic base or a salt thereof having an amino function and a molecular weight above 1,000. The flocculated cells are centrifuged, resuspended in water and precipitated by a water-miscible solvent, such as acetone. The cells which are simultaneously opened by the previous step are centrifuged away and again resuspended in water, whereby the enzyme is extracted from the cells. By addition of the organic base, mentioned above, to the suspension, the extracted cells, nucleic acids and ballast proteins are precipitated and are removed by centrifugation. The L-asparaginase is precipitated from the cell-free solution by addition of acetone. |