Critical role of different immobilized biocatalysts of a given lipase in the selective ethanolysis of sardine oil

Abstract

Different immobilized derivatives of two lipases were tested as catalysts of the synthesis of ethyl esters of omega-3 fatty acids during the ethanolysis of sardine oil in solvent-free systems at 25 °C. Lipases from Thermomyces lanuginosus (TLL) and Lecitase Ultra (a phospholipase with lipolytic activity) were studied. Lipases were adsorbed on hydrophobic Sepabeads C18 through the open active center and on an anion-exchanger Duolite with the active center exposed to the reaction medium. TLLSepabeads derivatives exhibit a high activity of 9 UI/mg of immobilized enzyme, and they are 20-fold more active than TLLDuolite derivatives and almost 1000-fold more active than Lipozyme TL IM (the commercial derivative from Novozymes). Lecitase-Sepabeads exhibit a high selectivity for the synthesis of the ethyl ester of EPA that is 43-fold faster than the synthesis of the ethyl ester of DHA.