Improving the extraction of intracellular L ‐asparaginase by high‐pressure homogenization

The effect of high‐pressure homogenization (HPH) on the primary extraction of intracellular L ‐asparaginase from Escherichia coli by aqueous two‐phase extraction (ATPE) has been investigated. When HPH was operated under a pressure of 120 MPa for four passages, 17.8% of L ‐asparaginase activity was lost. The addition of EOPO (a triblock copolymer of a central hydrophobic poly(propylene oxide) (PPO) block with hydrophilic poly(ethylene oxide) (PEO) blocks on each side) could improve the endurance of L ‐asparaginase to high pressure; while the existence of KHP (a mixture of KH 2 PO 4 and K 2 HPO 4 ) could strongly facilitate such deactivation. When HPH was operated in the ATPE system formed from EOPO and KHP, the recovery of L ‐asparaginase was greatly enhanced, as compared to the conventional HPH process. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.