fulltext.study @t Gmail

On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis

Paper ID Volume ID Publish Year Pages File Format Full-Text
24250 43507 2009 8 PDF Available
Title
On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis
Abstract

Free and immobilized lipases from Candida antarctica (CALA and CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) were used as catalysts in the synthesis of butyl propionate by transesterification in reaction media consisting in nine different ionic liquids. Enzyme activities were clearly dependent on the nature of the ions, the results being improving as the alkyl chain length of the imidazolium cation increased, and as a function of the type of anion ([PF6], [BF4] or [ethylsulphate]). The best synthetic activity (655.5 U/mg protein at 40 °C) was obtained when free CALB were assayed in the water-miscible IL cocosalkyl pentaethoxy methyl ammonium methosulfate ([CPMA][MS]), and was clearly related with the water content of the medium. The synthetic activity of free CALB in [CPMA][MS] was enhanced with the increase in temperature, while practically no effect was obtained for TLL. The ability of free CALB to synthesize aliphatic esters of different alkyl chain lengths, using different alkyl vinyl esters and 1-alkanols as substrates, was also studied in [CPMA][MS], the best results (4500 U/mg protein) being obtained for the synthesis of hexyl butyrate.

Keywords
Microbial lipases; Ionic liquids; Applied biocatalysis; Ester synthesis; Enzymes; Green chemistry
First Page Preview
On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Biotechnology - Volume 140, Issues 3–4, 25 March 2009, Pages 234–241
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering