Engineering of a high lipid producing Yarrowia lipolytica strain.
Engineering of a high lipid producing Yarrowia lipolytica strain.
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DOI：
10.1186/s13068-016-0492-3
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发表时间：
2016
影响因子：
6.3
通讯作者：
Brevnova EE
中科院分区：
文献类型：
--
作者：
Friedlander J;Tsakraklides V;Kamineni A;Greenhagen EH;Consiglio AL;MacEwen K;Crabtree DV;Afshar J;Nugent RL;Hamilton MA;Joe Shaw A;South CR;Stephanopoulos G;Brevnova EE
微生物脂质由许多产油生物体产生，包括特征良好的解脂耶氏酵母，可以通过上调脂质生物合成途径和下调或删除竞争途径来对其进行改造，以提高脂质产量。我们描述了一种以二酰基甘油酰基转移酶（DGA）基因过表达为中心的菌株工程策略，该策略应用过表达和缺失遗传靶标的组合筛选来构建高脂质生产酵母生物催化剂。由此产生的菌株 NS432 结合了来自圆红冬孢酵母的异源 DGA1 酶、来自麦角菌的异源 DGA2 酶以及天然 TGL3 脂肪酶调节因子的缺失。这三种基因修饰因其对脂质生产的影响而被选择，在分批发酵中实现了 77% 的脂质含量和每克葡萄糖 0.21 克脂质的产量。在补料分批葡萄糖发酵中，NS432 产生 85 g/L 脂质，生产率为 0.73 g/L/h。本研究报告的产量、生产率和滴度可能进一步支持经济高效、大规模微生物脂质生产用作生物燃料和生物化学品的应用目标。本文的在线版本 (doi:10.1186/s13068-016-0492-3) 包含补充材料，可供授权用户使用。
Microbial lipids are produced by many oleaginous organisms including the well-characterized yeast Yarrowia lipolytica, which can be engineered for increased lipid yield by up-regulation of the lipid biosynthetic pathway and down-regulation or deletion of competing pathways. We describe a strain engineering strategy centered on diacylglycerol acyltransferase (DGA) gene overexpression that applied combinatorial screening of overexpression and deletion genetic targets to construct a high lipid producing yeast biocatalyst. The resulting strain, NS432, combines overexpression of a heterologous DGA1 enzyme from Rhodosporidium toruloides, a heterlogous DGA2 enzyme from Claviceps purpurea, and deletion of the native TGL3 lipase regulator. These three genetic modifications, selected for their effect on lipid production, enabled a 77 % lipid content and 0.21 g lipid per g glucose yield in batch fermentation. In fed-batch glucose fermentation NS432 produced 85 g/L lipid at a productivity of 0.73 g/L/h. The yields, productivities, and titers reported in this study may further support the applied goal of cost-effective, large -scale microbial lipid production for use as biofuels and biochemicals. The online version of this article (doi:10.1186/s13068-016-0492-3) contains supplementary material, which is available to authorized users.