Heterologous Expression of Gene Encoded Thermostable Lipase and Lipolytic Activity

Abstract

Three lipase genes namely LK2, LK3 and LK5 were successfully sub-cloned into expression vector pET30a. The recombinant vectors were heterologically expressed into Escherichia coli BL21 (DE3) by 1 mM IPTG induced at 37 °C. The protein with the size of 32, 31 and 28 kDa with correspond to LK2, LK3 and LK5 clones were over expressed following SDS-PAGE analysis. Further analysis to quantity the level of expression showed that the protein were over expressed at around 30, 44 and 21 % of the total protein for LK2, LK3 and LK5 respectively. The lipolytic activity of the proteins by using lauric acid (C12) as substrate at 50°C, appeared that LK2 showed the highest activity among the other (1.49U/mg) followed by LK5 (1,10U/mg) and the lowest activity is LK3 (0.94U/mg).