Purification and immobilization of the soluble and insoluble portions of recombinant lipase by gram-positive enhancer matrix (GEM) particles

Abstract

Lipases are important enzyme for industries. In this work, the recombinant lipase with an AcmA tag working as purification and immobilization tag was expressed in Escherichia coli. Gram-positive enhancer matrix (GEM) particles work to purify and immobilize the recombinant lipase. GEM particles are produced by boiling the cells of Lactococcus lactis NZ9000 to remove the DNA and most proteins. GEM particles specifically bind protein with the AcmA tag in the C-terminal. The recombinant lipase was in two forms, the soluble part and the inclusion body. GEM particles could purify and immobilize the lipase from the soluble part in one step. After the inclusion body being dissolved by 8 M urea, the enzyme activity was recycled by the GEM particles. The GEM particles could immobilize over 75% of the enzyme activity. The lipase immobilized was a basophilla enzyme with the optimal temperature was 30 °C. The activity of the lipase immobilized was 47.1U/OD600 GEM particles at optimal conditions. The enzyme catalysis did not need the ions added to improve the activity. The GEM particles had excellent enzyme activity reusability.