Abstract
Two immobilized preparations from Thermomyces lanuginosus lipase (TLL) were compared in the synthesis of butyl butyrate. The commercial Lipozyme TL-IM, and TLL immobilized on styrene-divinylbenzene beads (MCI-TLL) were tested in the esterification reaction using n-hexane as solvent. The variables temperature (30-60 degrees C), substrate molar ratio (1:1 to 5:1), added water (0-1%), and biocatalyst content (3-40%) were evaluated in terms of initial reaction rate for each biocatalyst. SDS-PAGE analysis revealed that MCI-TLL had an immobilized enzymatic load twice as high as Lipozyme TL-IM, but with an activity 3-fold higher. MCI-TLL presented high initial reaction rates up to 1.0 M butyric acid, while Lipozyme TL-IM showed a decrease in its activity above 0.5 M. Moreover, MCI-TLL allowed a productivity of 14.5 mmol g(-1) h(-1), while Lipozyme TL-IM 3.2 mmol g(-1) h(-1), both by mass of biocatalyst. (C) 2013 Elsevier Ltd. All rights reserved.