Purification and Characterization of Organic Solvent Tolerant Lipase from Newly Isolated Pseudomonas aeruginosa FW_SH-1

In the present work, a novel solvent tolerant extracellular lipase from newly isolated Pseudomonas aeruginosa FW_SH-1 was purified by acetone precipitation and ion exchange chromatography. The purified lipase was characterized and compared with lipases obtained from other bacterial strains. A newly isolated strain that can produce organic solvent tolerant lipase was the aim of the present study, the strain was designated as FW_SH-1, that was identified as a Pseudomonas sp. The extracellular lipase from Pseudomonas aeruginosa FW_SH-1 was purified through acetone precipitation followed by Q-sepharose anion exchange chromatography. A final specific activity of 572 U/mg was achieved with 26.12 fold purification and an overall recovery of 10.21%. The molecular weight of the purified lipase was found to be 66 kDa using SDS polyacrylamide gel electrophoresis. The optimum pH and temperature for the activity of the purified lipase was found to be 8.0 and 45 oC. In the presence of hydrophilic solvents like methanol, ethanol, and propanol, the purified lipase remained stable. The presence of Ca2+, Mg2+, Na+, K+ and Tween 20 stimulated the activity of the purified lipase. The metal ions such as Ca2+, Mg2+, Na+, K+ and Tween (20 and 80) as surfactants were found to enhance the relative activity. The organic solvents such as methanol, ethanol and propanol had a very little effect in deactivating the lipase.