The extracellular production of T1 lipase was performed by co-expression of pJL3 vector encoding bacteriocin release protein in prokaryotic system. Secretory expression was optimized by considering several parameters, including host strains, inducer (IPTG) concentration, media, induction at A(600nm), temperature, and time of induction. Among the host strains tested, Origami B excreted out 18, 100 U/ml of lipase activity into culture medium when induced with 50 mu M IPTG for 12 h. The Origami B harboring recombinant plasmid pGEX/T1S and pJL3 vector was chosen for further study. IPTG at 0.05 mM, YT medium, induction at A(600 nm) of 1,25, 30 degrees C, and 32 h of induction time were best condition for T1 lipase secretion with Origami B as a host. (c) 2005 Elsevier Inc. All rights reserved.