Identification and characterization of fatty acid desaturases in Schizochytrium sp. HX-308
Identification and characterization of fatty acid desaturases in Schizochytrium sp. HX-308
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DOI：
10.1016/j.algal.2022.102861
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
Yu Jia;Yu-Zhou Wang;Fang-Tong Nong;Wang Ma;Pengwei Huang;Xiaoman Sun
中科院分区：
文献类型：
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作者：
Yu Jia;Yu-Zhou Wang;Fang-Tong Nong;Wang Ma;Pengwei Huang;Xiaoman Sun
裂殖壶菌（Schizochytrium sp.）作为一种有前途的破囊壶菌，因其能产生高水平的多不饱和脂肪酸而受到广泛关注。裂囊藻属HX-308具有完整的厌氧聚酮合成酶（PKS）途径和不完全的有氧去饱和酶/延长酶途径。然而，尚不清楚哪些脂肪酸去饱和酶参与裂殖壶菌的脂肪酸去饱和。以及它们是如何协调行动的在这项工作中，我们首先确定了五个推定的去饱和酶在Schizochytriumsp。HX-308，包括Δ 12、两个Δ 8、Δ 6和Δ 5脂肪酸去饱和酶基因。它们在解脂耶氏酵母中异源表达，并且前四种脂肪酸去饱和酶被验证为功能性的。Δ 12去饱和酶的作用使C18：2 Δ 9，12脂肪酸含量从17.26%增加到28.46%。两种Δ 8去饱和酶的表达使C20：3 Δ 8，11，14的含量分别从3.84%提高到7.29%和6.82%。Δ 6去饱和酶使PO1F菌株产生一种新的脂肪酸C18：3 Δ 6，9，12，达到总脂肪酸的9.73%。Δ 5去饱和酶的表达虽然不产生C20：4 Δ 5，8，11，14脂肪酸，但显著降低了C18：1 Δ 9和C18：2 Δ 9，12脂肪酸的含量，并显著增加了C18：3 Δ 6，9，12和C20：2 Δ 11，14脂肪酸的含量。本研究为裂殖壶菌多不饱和脂肪酸组成的优化提供了有价值的参考。在未来通过基因工程。
As a promising species of the thraustochytrids, Schizochytrium sp. has attracted extensive attention due to its ability to produce high levels of polyunsaturated fatty acids. InSchizochytriumsp. HX-308, there was a complete anaerobic polyketide synthase (PKS) pathway and an incomplete aerobic desaturase/elongase pathway. However, it is still quite unclear which fatty acid desaturases are involved in fatty acid desaturation inSchizochytriumsp. and how they act in concert. In this work, we firstly identified five putative desaturases inSchizochytriumsp. HX-308, including Δ12, two Δ8, Δ6, and Δ5 fatty acid desaturase genes. They were heterologously expressed in Yarrowia lipolytica and the first four fatty acid desaturases were verified as functional. Δ12 desaturase contributes to a significant increase in the content of C18:2Δ9, 12fatty acids, from 17.26 % to 28.46 %. The expression of two Δ8 desaturases resulted in an increase in C20:3Δ8, 11, 14content, from 3.84 % to 7.29 % and 6.82 %, respectively. Δ6 desaturase enables the PO1F strain to produce a new fatty acid C18:3Δ6, 9, 12, reaching 9.73 % of the total fatty acids. Although the expression of Δ5 desaturase didn't produce C20:4 Δ5, 8, 11, 14fatty acids, it significantly decreased the content of C18:1Δ9and C18:2Δ9, 12fatty acids and largely significantly increased C18:3Δ6, 9, 12and C20:2Δ11, 14fatty acid content. This work will provide valuable insights into the optimization of the polyunsaturated fatty acid composition ofSchizochytriumsp. through genetic engineering in the future.