Hydrolytic and Transesterification Activities of Thermostable Lipase ITB1.1

Heterologous expression of local thermostable lipase (Lipase ITB1.1) has been carried out by using pET-30a(+) vector in Escherichia coli BL21(DE3). SDS-PAGE analysis showed that the protein size is around 50 kDa. Hydrolytic activity was determined at 70 [degrees]C and pH 8 by using p-Nitrophenyl palmitate (pNPP) as substrate. The activity of partial purified enzyme was significantly increased (0.56 U/mg) compared to that the crude extract (0.25 U/mg). Lipase ITB 1.1 has highest specific activity (1.23 U/mg) at 85 [degrees]C and pH 9.5. Further, characterization of the enzyme suggested that the enzyme exhibited transesterification activity. GC-MS spectra of the reaction product indicated that the coconut oil (substrate) was converted into methyl esters. The results suggesting that Lipase ITB1.1 is potential enzyme for biodiesel production.