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.

中文翻译：

---

脂肪酶催化二十二碳六烯酸 (DHA) 与固定化洋葱假单胞菌和疏毛型嗜热丝孢菌的酯化

已经研究了月桂醇使用固定化洋葱假单胞菌(PCL) 和疏毛嗜热丝孢菌脂肪酶 (TLL)催化酯化合成金枪鱼游离脂肪酸 (TFFA) 的选择性行为。使用粒度分析仪、BET 方法和 FT-IR 对固定化 PCL 和 TLL 及其载体 immobead-150 进行表征。合适的反应条件已确定为月桂醇与 TFFA 的比例为 4:1 (wt/wt)，pH 8.0，缓冲液与 TFFA 的比例 1:1 (wt/wt)，温度 50°C 和搅拌速度 800 rpm。还进行了两种固定化脂肪酶的酯化重复使用，在重复使用固定化 PCL 和 TLL 5 个循环后，活性分别稳定在 60.9% 和 47.6%。16 小时后，在具有固定化 PCL 的酯中回收了最多 93.8 wt% 的二十二碳六烯酸。