Enzymatic esterification of saturated fatty acids with aliphatic alcohols as an alternative method of a low-temperature synthesis of esters

Abstract

low-temperature synthesis of saturated fatty acid esters with aliphatic alcohols by enzymatic esterification in the presence of heterogeneous biоcatalysts was suggested. The biоcatalysts were prepared by immobilization of recombinant rPichia/lip lipase on mesoporous silica. A comparison of the reaction rates was used to make up a matrix of biоcatalyst activities and determine a pair of acid/alcohol substrates, for which a maximum esterification rate was observed. A high activity of biоcatalysts was observed in the esterification of fatty acids with seven or more carbon atoms in the molecule. The rate of esterification of fatty acids with primary alcohols (n-C₃—C₁₆ or iso-С₅) was two orders of magnitude higher than that with secondary alcohols (sec-С₃—С₄). The silica-immobilized rPichia/lip lipase possessed a high operational stability; the biocatalyst operated without loss of activity for hun-dreds of hours at 18—22 °С in a non-traditional for enzymes medium of organic solvents.