Characterization of a lipase from a newly isolated Pseudomonas sp.

Background and Objectives: Lipases are valuable biocatalysts which are widely used in the detergent, food, dairy and pharmaceutical industries. The aims of the present study included the isolation of a lipase-producer from industrial zones and the partial characterization of the enzyme. Materials and Methods: A number of bacteria were isolated from sites related to the oil industries. An isolate forming a halo zone in a selective medium (TW agar) was then selected and grown on a medium suitable for the production of lipase. The isolate was subsequently identified by the 16S rRNA sequencing method, and its enzyme activity was measured by a spectrophotometer using pNPP as a substrate. Results: The selected isolate was identified by the molecular method as Pseudomonas sp. Its extracellular lipase activity was 41.5 +/- 1.4 U/ml, and the high affinity of this enzyme for the substrate was indicated by the kinetic parameters of Km and Vm, which were estimated by the the Lineweaver-Burk plot as 0.77 mM and 49.5 U/ml, respectively. Activation energy of lipase calculated from the Arrhenius plot was found to be 20.78 kJ/mol, and a temperature coefficient (Q10) of 4.39 indicated the high catalytic activity of the enzyme and the temperature dependence of the enzymatic reaction. Conclusion: The results demonstrated that the indigenous isolate could have potential applications in many relevant industries.