Purification and properties of the lipases from Rhodotorula pilimanae Hedrick and Burke |
| |
Authors: | J M Muderhwa R Ratomahenina M Pina J Graille P Galzy |
| |
Institution: | (1) Chaire de Génétique et Microbiologie, ENSA-INRA, F-34060 Montpellier Cedex, France;(2) Division Chimie des Corps Gras, CIRAD-IRHO, B.P. 5035, F-34032 Montpellier Cedex, France |
| |
Abstract: | Summary 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-1 for lipase I and 12.4 kcal·mole-1 for lipase II. The inactivation energies were about 21.9 and 17.7 kcal·mole-1 for lipase I and lipase II, respectively. The enzymes are slightly inhibited by Cu2+, Co2+, Hg2+, Mn2+, 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. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|