Lipase catalyzed esterification of Docosahexaenoic acid (DHA) with immobilized Pseudomonas cepacia and Thermomyces lanuginosus

Abstract

The selective behaviour of lauryl alcohol to catalyze esterification for the synthesis of tuna free fatty acids (TFFAs) using immobilized Pseudomonas cepacia (PCL) and Thermomyces lanuginosus lipases (TLL) have been investigated. The characterization of both immobilized PCL and TLL and their support immobead-150 is carried out using particle size analyzer, BET method and FT-IR. The suitable reaction conditions have been determined as lauryl alcohol to TFFAs ratio 4:1 (wt/wt), pH 8.0, buffer to TFFAs ratio 1:1 (wt/wt), temperature 50°C and agitation speed 800 rpm. Reusability of both the immobilized lipases for esterification has also been carried out and the activity was stabilized at 60.9% and 47.6% after 5 cycles of repeated use of immobilized PCL and TLL, respectively. Maximum 93.8 wt% Docosahexaenoic acid is recovered in esters with immobilized PCL after 16 h.