Identity and lipase activity of an isolate of Thermoactinomyces vulgaris

Elwan, S. H.; Mostafa, Shaimaa; Khodair, A.A.; Ali, Omkolthoum

doi:10.1016/s0323-6056(78)80078-0

Cited by 4 publications

(3 citation statements)

References 5 publications

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“…These values are close to the optima reported for Bacillus thermoleovorans ID-1 lipases [4,18], for Bacillus thermocatenulatus lipases [5,18], for the lipase produced by Thermoactinomyces vulgaris [6] and the lipase produced by Bacillus circulans [21].…”

Section: Enzyme Characterisationsupporting

confidence: 87%

“…2b). The requirement of yeast extract for growth at 60 C was indicative of the loss of synthetic abilities, reported to occur in certain bacterial thermophiles [6]. Olive oil was found to support growth and did not cause inhibition even when the concentration was increased to 10% [v/v].…”

Section: Growth Requirements and Physiologymentioning

confidence: 99%

“…The lipase produced by Bacillus thermocatenulatus retained only 50 % of its activity after 30 minutes of incubation at 60 C [5]. The lipase produced by Thermoactinomyces vulgaris lost all activity after 5 minutes of incubation at 90 C [6]. The esterase produced by Bacillus licheniformis had a half-life of 1 h at 64 C [20], while the lipase produced by Bacillus stearothermophilus was only stable up to 55 C for 30 minutes of incubation [22].…”

Section: Enzyme Characterisationmentioning

confidence: 99%

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A Novel Olive Oil Degrading Thermoactinomyces Species with a High Extremely Thermostable Lipase Activity

Al-Khudary

Hashwa²,

Mroueh

2004

Engineering in Life Sciences

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A filamentous, Gram-positive, spore forming aerobic bacterium was isolated from olive oil contaminated soil (Al Koura, Lebanon) on rhodamine agar plates at 60 C. The isolate, HRK-1 produced large quantities of an extracellular thermostable lipase which degrades olive oil. It was primarily classified as a Thermoactinomyces sp. due to the filamentous structure of its cells that bear one spore each on an un-branched sporophore, the resistance of its spores to boiling, utilisation 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 rpm. It showed an efficient olive oil degrading ability. No traces of triolein were detected after a 36-h 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 optimum concentration of olive oil for lipase activity was 1 % [v/v], and the activity was not enhanced at higher concentrations, but on the contrary, a decrease in enzyme activity was recorded. The lipase of HRK-1 was preliminarily characterised in the crude cell-free supernatant with a specific activity of 0.14 U/mg. It has an optimum activity at 60 C and a pH of 8.0. This lipolytic enzyme showed resistance to boiling and to a wide range of metallic ions and inhibitors. The formation of this heat-stable lipase started in the early exponential growth phase, while a maximum 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/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.

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