| Autor: |
Muderhwa, J., Ratomahenina, R., Pina, M., Graille, J., Galzy, P. |
| Zdroj: |
Applied Microbiology & Biotechnology; 1986, Vol. 23 Issue 5, p348-354, 7p |
| Abstrakt: |
The Rhodotorula pilimanae CBS 5804 strain secretes into the culture medium two lipases: their pH optima are 4 and 7. The two lipases were purified by precipitation with acetone followed by chromatography on SP-Sephadex C50 and Sephadex G200. The purification factors achieved in comparison with the supernatant culture were x74 for lipase I and x90 for lipase II. The molecular weights were estimated at 172,800 and 21,400 for lipase I and lipase II, respectively. Their activities are optimal between 45°C and 55°C. The activation energies were 5.9 kcal·mole for lipase I and 12.4 kcal·mole for lipase II. The inactivation energies were about 21.9 and 17.7 kcal·mole for lipase I and lipase II, respectively. The enzymes are slightly inhibited by Cu, Co, Hg, Mn, N-acetylacetone, acetic acid and sodium lauryl sulphate. EDTA did not affect their enzymatic activity. These two lipases are secreted in the culture media in the absence of inducer; their biosynthesis is not inhibited by glucose. These lipases hydrolyse primarily the 1-(or 3-)position of all triglycerides tested. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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