Isolation, identification, biochemical properties and potential application of an organic solvent-tolerant lipase from Pseudomonas sp. strain NEB-1

Using enrichment procedures, 45 organic solvent-tolerant lipase producer bacterial strains were screened from areas contaminated by oil and organic solvents. Among the strains, 15 isolates exhibited extreme stability toward organic solvents and high lipolytic activity. The NEB-1 isolate which was later identified as Pseudomonas sp. strain NEB-1 by biochemical tests and 16S rDNA gene sequence analysis was selected based on extremely high tolerance to organic solvents and maximum lipase production. Biochemical studies revealed that the crude lipase was stable at temperatures between 20 oC and 60 oC and pH ranges of 4 to 11 for 1 h. Optimum pH and temperature of the enzyme were revealed to be 9.5 and 70 oC, respectively. The crude lipase showed remarkable tolerance in presence of different organic solvents with a broad range of hydrophobicity characteristics. The solvent stable lipase showed an attractive potency for application in biocatalysis in non-aqueous systems and biodiesel production.