Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
Research Unit for Physiological Chemistry, Kyoto University, Kyoto, Japan.
Biosci Biotechnol Biochem. 2021 Apr 24;85(5):1252-1265. doi: 10.1093/bbb/zbaa123.
ω3 Polyunsaturated fatty acids are currently obtained mainly from fisheries; thus, sustainable alternative sources such as oleaginous microorganisms are required. Here, we describe the isolation, characterization, and application of 3 novel ω3 desaturases with ω3 polyunsaturated fatty acid-producing activity at ordinary temperatures (28 °C). First, we selected Pythium sulcatum and Plectospira myriandra after screening for oomycetes with high eicosapentaenoic acid/arachidonic acid ratios and isolated the genes psulω3 and pmd17, respectively, which encode ω3 desaturases. Subsequent characterization showed that PSULω3 exhibited ω3 desaturase activity on both C18 and C20 ω6 polyunsaturated fatty acids while PMD17 exhibited ω3 desaturase activity exclusively on C20 ω6 polyunsaturated fatty acids. Expression of psulω3 and pmd17 in the arachidonic acid-producer Mortierella alpina resulted in transformants that produced eicosapentaenoic acid/total fatty acid values of 38% and 40%, respectively, at ordinary temperatures. These ω3 desaturases should facilitate the construction of sustainable ω3 polyunsaturated fatty acid sources.
ω3 多不饱和脂肪酸目前主要从渔业中获得；因此，需要可持续的替代来源，如油脂微生物。在这里，我们描述了 3 种新型 ω3 去饱和酶的分离、鉴定和应用，这些酶在常温（28°C）下具有产生 ω3 多不饱和脂肪酸的活性。首先，我们在筛选具有高二十碳五烯酸/花生四烯酸比例的卵菌后，选择了腐霉属和螺旋藻，并分别分离出编码 ω3 去饱和酶的基因 psulω3 和 pmd17。随后的鉴定表明，PSULω3 在 C18 和 C20 ω6 多不饱和脂肪酸上均具有 ω3 去饱和酶活性，而 PMD17 仅在 C20 ω6 多不饱和脂肪酸上具有 ω3 去饱和酶活性。psulω3 和 pmd17 在花生四烯酸产生菌枝顶孢霉中的表达导致转化体在常温下分别产生二十碳五烯酸/总脂肪酸值为 38%和 40%。这些 ω3 去饱和酶应该有助于构建可持续的 ω3 多不饱和脂肪酸来源。
