Lipase-catalyzed ethanolysis of borage oil: a kinetic study.
Ethanolysis of borage oil catalyzed by two commercial lipases (from Pseudomonas cepacia and Candida antarctica) was studied using two different methodologies. Multiresponse models derived from a generalized Michaelis-Menten mechanism were utilized to describe the rates of formation of ethyl esters of the primary fatty acids present in the precursor oil. The relative rate constants determined for each of the fatty acid residues indicated that both lipases discriminate against release of gamma-linolenic acid residues under the reaction conditions studied. However, both lipases also released some of the residues located at the sn-2 position, indicating that for the experimental conditions studied, both lipases are nonspecific. Moreover, inactivation of Novozym 435 was rapid. Because the half-life of this enzyme (ca. 2.2 h) is comparable to the half-life of the reaction, the intrinsic reaction rate and enzyme deactivation must both be considered in modeling the kinetics.
Torres
Carlos F
CF
Instituto de Catálisis y Petroleoquímica, CSIC, Departamento de Biocatálisis, Campus Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain.
Hill
Charles G
CG
Otero
Cristina
C
D016956:Burkholderia cepacia / Q000201:enzymology*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D003198:Computer Simulation; D004789:Enzyme Activation; D004795:Enzyme Stability; D000431:Ethanol / Q000737:chemistry*; D005227:Fatty Acids / Q000138:chemical synthesis*; D005656:Fungal Proteins; D007700:Kinetics; D008049:Lipase / Q000737:chemistry*; D008956:Models, Chemical; D010938:Plant Oils / Q000737:chemistry*; D017965:gamma-Linolenic Acid
D005227:Fatty Acids; D005656:Fungal Proteins; D010938:Plant Oils; D000431:Ethanol; D017965:gamma-Linolenic Acid; D008049:Lipase; C431349:lipase B, Candida antarctica; C079363:borage oil