Parietichytrium sp. 中依赖于 PUFA 合酶的 DHA 合成途径及其改造生产 EPA 和 n-3DPA。

PUFA synthase-independent DHA synthesis pathway in Parietichytrium sp. and its modification to produce EPA and n-3DPA.

机构信息

Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, 819-0395, Japan.

Central Research Laboratory, Nippon Suisan Kaisha, Ltd., Tokyo, 192-0991, Japan.

出版信息

Commun Biol. 2021 Dec 9;4(1):1378. doi: 10.1038/s42003-021-02857-w.

DOI:10.1038/s42003-021-02857-w

PMID:34887503

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8660808/

Abstract

The demand for n-3 long-chain polyunsaturated fatty acids (n-3LC-PUFAs), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), will exceed their supply in the near future, and a sustainable source of n-3LC-PUFAs is needed. Thraustochytrids are marine protists characterized by anaerobic biosynthesis of DHA via polyunsaturated fatty acid synthase (PUFA-S). Analysis of a homemade draft genome database suggested that Parietichytrium sp. lacks PUFA-S but possesses all fatty acid elongase (ELO) and desaturase (DES) genes required for DHA synthesis. The reverse genetic approach and a tracing experiment using stable isotope-labeled fatty acids revealed that the ELO/DES pathway is the only DHA synthesis pathway in Parietichytrium sp. Disruption of the C20 fatty acid ELO (C20ELO) and ∆4 fatty acid DES (∆4DES) genes with expression of ω3 fatty acid DES in this thraustochytrid allowed the production of EPA and n-3docosapentaenoic acid (n-3DPA), respectively, at the highest level among known microbial sources using fed-batch culture.

摘要

在不久的将来，人们对 n-3 长链多不饱和脂肪酸（n-3LC-PUFAs）的需求将超过其供应量，因此需要一种可持续的 n-3LC-PUFA 来源。甲藻是一类海洋原生生物，其特征是通过多不饱和脂肪酸合酶（PUFA-S）进行厌氧生物合成 DHA。对自制草案基因组数据库的分析表明，Parietichytrium sp. 缺乏 PUFA-S，但拥有合成 DHA 所需的所有脂肪酸延长酶（ELO）和去饱和酶（DES）基因。通过反向遗传学方法和使用稳定同位素标记脂肪酸的示踪实验表明，ELO/DES 途径是 Parietichytrium sp. 中 DHA 合成的唯一途径。在这种甲藻中敲除 C20 脂肪酸 ELO（C20ELO）和 ∆4 脂肪酸 DES（∆4DES）基因，并表达 ω3 脂肪酸 DES，可在分批补料培养中使 EPA 和 n-3 二十二碳五烯酸（n-3DPA）的产量达到已知微生物来源中的最高水平。