title: Lipase-catalyzed solvent-free transesterification of wood sterols.
abstract: Eighteen commercial lipase preparations, either immobilized or crude enzyme powders, were screened for the transesterification of wood sterols. The reactions were carried out in a solvent-free system, at the optimum temperature of the enzyme preparations as reported by the manufacturer and at the pressure of 2 mbar, with 5 or 10% in weight of the enzyme relative to the wood sterol content of the reacting mixture. Methyl esters of sunflower fatty acids were used as transesterifying agent. Of all the enzymes assayed, only Lipase TL from Pseudomonas stutzeri PL-836 (Meito Sangyo) exhibited any significant transesterifying capacity, 85 and 95% of conversion after 2 and 8 h of reaction, respectively, when 10% in weight of enzyme was used.
authors.affiliation: School of Biochemical Engineering, Catholic University of Valparaíso, Av. Brazil 2147, PO Box 4059, Valparaíso, Chile.
authors.forename: Irene
authors.initials: I
authors.lastname: Martínez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Markovits
authors.forename: Rolando
authors.initials: R
authors.lastname: Chamy
authors.forename: Andrés
authors.initials: A
authors.lastname: Markovits
mesh_terms: D004951:Esterification; D004952:Esters; D005227:Fatty Acids / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry* / Q000145:classification*; D010865:Pilot Projects; D010938:Plant Oils / Q000737:chemistry*; D044223:Pseudomonas stutzeri / Q000201:enzymology*; D012997:Solvents / Q000737:chemistry; D013045:Species Specificity; D013261:Sterols / Q000737:chemistry*; D000074242:Sunflower Oil; D014934:Wood
chemical_list: D004952:Esters; D005227:Fatty Acids; D010938:Plant Oils; D012997:Solvents; D013261:Sterols; D000074242:Sunflower Oil; D008049:Lipase