Transester Activity of Lipase from Pseudomonas sp. LPG171 Immobilized on Lampung Natural Zeolite
Dian Herasari (1*), Bunga Mega Nurlinda (1), Mita Rilyanti (1), John Hendri (1)

(1) Department of Chemistry, FMIPA, Universitas Lampung
* dian.herasari[at]fmipa.unila.ac.id

Abstract

This study aims to determine the transester activity of the lipase enzyme Pseudomonas sp. LPG171 immobilized on Lampung natural zeolite (ZAL). The research stages began with the production of lipase from the bacteria Pseudomonas sp. LPG171, purification of lipase by ammonium sulfate fractionation and gel filtration column chromatography using Sephadex G5. The pure enzyme was then immobilized using ZAL from CV Minatama, Lampung. The immobilization process was evaluated by comparing the transester activity of free enzyme and immobilized enzyme at optimum enzyme conditions. Lipase hydrolysis activity was determined using the Kwon and Rhee method, while transesterification activity was determined using the Fu method. Concentration of protein was calculated based on the Lowry method.

The results showed that the specific activity of lipase activity Pseudomonas sp. LPG171 increased at each purification stage, respectively by 21.25 U per mg for the enzyme crude extract, 94.95 U per mg for the ammonium sulfate fraction after dialysis, and 480.44 U per mg for the column chromatography fraction. The optimum conditions for immobilized lipase for its transester activity reached on pH 7, temperature 40degree Celcius, and incubation time of 10 minutes did not change compared to the free enzyme, except for the optimum temperature which shifted 5 degrees higher than the free enzyme. Repeated use of immobilized lipase up to 5 times reduced lipase activity by up to 45.31 percent.

Keywords: Lipase, Pseudomonas sp. LPG171, immobilization, and Lampung natural zeolite

Topic: Chemistry