This work attempts to achieve the enrichment of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in acylglycerols as well as biodiesel production by investigating the performance of various lipases in ethanolysis. The ethanolysis activities of five immobilized lipases in decreasing order were as follows: Lipozyme TL IM, Novozym 40086/Lipozyme RM IM, Novozym 435 and Rhizopus oryzae lipase immobilized on polypropylene (RO PP). EPA could be enriched to a certain content by Lipozyme TL IM, Novozym 40086, Lipozyme RM IM, and RO PP. The enrichment of DHA was achieved well by those four sn-1,3 regioselective lipases, and DHA contents in acylglycerols were the highest when Lipozyme TL IM and Novozym 40086 were used, reaching 2.87-fold and 2.81-fold of the initial content. However, Novozym 435 could not enrich EPA and DHA effectively. Fatty acid ethyl esters produced in this work contained abundant palmitic acid and palmitoleic acid, which could be ideal biodiesel considering their chain length. The competitive factors of five lipases towards DHA were all significantly higher than those towards EPA. When Lipozyme TL IM and Novozym 40086 achieved the maximum DHA contents, their DHA recoveries in acylglycerols reached 91.87% and 89.00%, respectively. The DHA recoveries were all significantly higher than the corresponding EPA recoveries in the reactions catalyzed by five lipases. Moreover, Lipozyme TL IM could be a potential lipase for the separation of EPA and DHA. This study may promote the full use of fish oil and broaden the application of lipases.

中文翻译：

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通过酶乙醇解富集 EPA 和 DHA：疏棉状嗜热丝孢菌、米赫根毛霉、米根霉和南极假丝酵母脂肪酶的作用


本工作试图通过研究各种脂肪酶在乙醇分解中的性能，实现酰基甘油中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的富集以及生物柴油的生产。 5种固定化脂肪酶的乙醇分解活性从高到低依次为：Lipozyme TL IM、Novozym 40086/Lipozyme RM IM、Novozym 435和聚丙烯固定化米根霉脂肪酶(RO PP)。 Lipozyme TL IM、Novozym 40086、Lipozyme RM IM、RO PP可以将EPA富集到一定含量。这四种sn-1,3区域选择性脂肪酶对DHA的富集效果很好，其中使用Lipozyme TL IM和Novozym 40086时酰基甘油中的DHA含量最高，分别达到初始含量的2.87倍和2.81倍。然而，Novozym 435 无法有效富集 EPA 和 DHA。本工作生产的脂肪酸乙酯含有丰富的棕榈酸和棕榈油酸，考虑到其链长，这可能是理想的生物柴油。 5种脂肪酶对DHA的竞争因子均显着高于对EPA的竞争因子。当Lipozyme TL IM和Novozym 40086达到最大DHA含量时，它们在酰基甘油中的DHA回收率分别达到91.87%和89.00%。在五种脂肪酶催化的反应中，DHA 回收率均显着高于相应的 EPA 回收率。此外，Lipozyme TL IM 可能是一种用于分离 EPA 和 DHA 的潜在脂肪酶。该研究可促进鱼油的充分利用，拓宽脂肪酶的应用。