Cloning, expression and characterization of chimeric BacillusThermocatenulatus Lipase in E.coli

Bacterial lipases are members of α/β hydrolase family that hydrolyzed triacylglycerol at the water- lipid interface. Bacillus thermocatenulatus lipase 2 (BTL2) is a thermoalkalophilic lipase that shows optimal activity at 60–75 oC and pH 8–10. BTL2 is an important research target because of its potential industrial applications. At the present study chimeric Bacillus thermocatenulatus lipase contain the consensus sequence of Candida rugosa lipase (207Gly-Glu-Ser-Ala-Gly211) at the nucleophilic elbow region was cloned and expressed in E. coli as secretion protein. Finally, Catalytic activity of chimeric lipases was evaluated at presence of various triglycerides as substrates and the effects of different parameters such as temperature, pH, detergents, organic solvents and metal ions were evaluated on chimeric enzyme activity using a pH-stat assay. The results showed that the chimeric enzyme is most active to C4 substrate, (pH 9.0) and 60 oC. As well as enzyme activity has increased in the presence of organic solvents, N-Hexane, N-heptane, methanol, chloroform and detergents such as Triton X -100, Tween 20, Tween 40. Also, metal ions, respectively decreased general effect on the enzyme activity in chimeric lipase.