Characterization of a lipase from a newly isolated Pseudomonas sp

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.

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.

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.

The results demonstrated that the indigenous isolate could have potential applications in many relevant industries.