Isolation and study of Lipase activity of an olive oil degrading Thermoactionomyces SP. (c2002)

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dc.contributor.author Al Khudary, Rami
dc.date.accessioned 2011-11-16T07:52:15Z
dc.date.available 2011-11-16T07:52:15Z
dc.date.copyright 2002 en_US
dc.date.issued 2011-11-16
dc.date.submitted 2002-06-12
dc.identifier.uri http://hdl.handle.net/10725/988
dc.description.abstract A ftlamentous, Gram-Positive, spore forming filamentous bacterium was isolated from soil (AI Koura - Lebanon) on rhodamine agar plates at 60°C. The isolate, HRK-l produced large quantities of an extra cellular thermostable lipase that degrades olive oil. It can be primarily classified as Thermoactynomyces putidus due to filamentous structure of its molecules that bear one spore each on an un-branched sporophore, the resistance of its spores to boiling, utilization of sucrose as a carbon source and production of dark pigments. The isolate grew optimally at a temperature of 60°C, a pH of 7.3, and an orbital shaking of 250 r.p.m. It showed an efficient olive oil degrading ability. No traces of triolein were detected after 36 hours of cultivation. A concentration of 10% (v/v) olive oil did not inhibit its growth. Lipase production was constitutive, and did not depend on the presence of olive oil. The optimal concentration of olive oil for lipase activity was 1 % (v /v), and activity was not enhanced at higher concentrations, but on the contrary, a decrease in enzyme activity was recorded. The lipase HRKL-1 was bio-chemically characterized. It has a molecular weight of 80 k-Daltons and an optimal activity at 60°C and pH 8.0. This lipolytic enzyme showed resistance to boiling and to a wide range of metallic 10ns and inhibitors. It was only slightly inhibited by PMSF (phenylmethylsulfonyl fluoride), while its activity increased in the presence of Ca ++ ions. The Km value for HRKL-1 (0.021 mM) indicated high affiniity of the enzyme to its substrate. The formation of this heat-stable lipase started in the early exponential growth phase, while maximal extracellular enzyme activity was detected at the end of the decline phase, when most of the cells appeared as spherical spores. The exceptionally high activity of lipase (2.37 U I ml) produced by HRK-1 measured in the cell free supernatant clearly indicated the commercial importance of this isolate, especially after it showed great stability at elevated temperatures. en_US
dc.language.iso en en_US
dc.subject Lipase en_US
dc.subject Food spoilage en_US
dc.subject Olive oil en_US
dc.title Isolation and study of Lipase activity of an olive oil degrading Thermoactionomyces SP. (c2002) en_US
dc.type Thesis en_US
dc.term.submitted Spring en_US
dc.author.degree MS in Biology en_US
dc.author.school Arts and Sciences en_US
dc.author.commembers Dr. George Baroody
dc.author.commembers Dr. Mohamad Mroueh
dc.author.woa RA en_US
dc.description.physdesc 1 bound copy: 83 leaves; ill. Available at RNL. en_US
dc.author.division Biology en_US
dc.author.advisor Dr. Constantine Daher
dc.identifier.doi https://doi.org/10.26756/th.2002.19 en_US
dc.publisher.institution Lebanese American University en_US

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