An effective method for extraction of glutaryl-7-aminocephalosporanic acid acylase from recombinant E. coli cells

In this study, several chemical treatment techniques commonly used for protein extraction were investigated for recovering glutaryl-7-aminocephalosporanic acid acylase (GLA) from recombinant E. coli cells. The best results were obtained by the combined use of cetyltrimethylammonium bromide (CTAB) and KCl. Subsequently, various extraction conditions, such as cation salt, concentrations of CTAB and KCl, extraction temperature, extraction time, and biomass, were optimized to further enhance the release yield and specific activity of GLA. Our results showed that 110% of GLA was released after treatment with 0.5% CTAB (w/v, %) and 0.3 M KCl at 10°C for 12 h, and its specific activity in this extracting solution was approximately 1.5 times higher as compared to that obtained by sonication. This extraction method could avoid the inactivation of GLA caused by drastic mechanical methods, and also enhance its specific activity for industrial extraction.