The lipases of P. aeruginosa were isolated, immobilized and characterized. They were applied to hydrolysis of crude oils i.e. cotton oil, maize oil, palm oil,
sunflower oil and olive oil. The lipase produced by P. aeruginos8 was precipitated
from the growth media using by cold acetone and was immobilized on celite. The
characteristics of free and immobilized lipases were studied as follows: The optimum ternperature for Iipases activity was 37°C for free lipase.
whereas it was 44°C for immobilized one. The optimum pH value for free and
Immobilized lipases was 7.4. The stability to pH was higher in Ihe Immobifized
enzyme than the free one. Immobilized lipase was stable between pH 6.8-7.8 and
tree lipase between 7.2-7.6. Both free and immobilized lipases were stable at 40·C
but immobilized one was more stable at (4'J-SO°C). The optimum substrate
concentrations for free and immobilized Iipases were 0.25% and 0.30"/0, respectively.
Free and immobilized lipases were able 10 hydrolyse all natural oils tested. Olive olf
was the most hydrolyzed one than other oils.