Ferreira Raphael, Teixeira Paulo Gonçalves, Gossing Michael, David Florian, Siewers Verena, Nielsen Jens
Department of Biology and Biological Engineering, Chalmers University of Technology, SE412 96 Gothenburg, Sweden.
Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE412 96 Gothenburg, Sweden.
Metab Eng Commun. 2018 Feb 3;6:22-27. doi: 10.1016/j.meteno.2018.01.002. eCollection 2018 Jun.
Triacylglycerols (TAGs) are valuable versatile compounds that can be used as metabolites for nutrition and health, as well as feedstocks for biofuel production. Although is the favored microbial cell factory for industrial production of biochemicals, it does not produce large amounts of lipids and TAGs comprise only ~1% of its cell dry weight. Here, we engineered to reorient its metabolism for overproduction of TAGs, by regulating lipid droplet associated-proteins involved in TAG synthesis and hydrolysis. We implemented a push-and-pull strategy by overexpressing genes encoding a deregulated acetyl-CoA carboxylase, , as well as the last two steps of TAG formation: phosphatidic phosphatase () and diacylglycerol acyltransferase (), ultimately leading to 129 mg∙gCDW of TAGs. Disruption of TAG lipase genes , , and sterol acyltransferase gene increased the TAG content to 218 mg∙gCDW. Further disruption of the beta-oxidation by deletion of , as well as glycerol-3-phosphate utilization through deletion of , did not affect TAGs levels. Finally, disruption of the peroxisomal fatty acyl-CoA transporter led to accumulation of 254 mg∙gCDW. The TAG levels achieved here are the highest titer reported in , reaching 27.4% of the maximum theoretical yield in minimal medium with 2% glucose. This work shows the potential of using an industrially established and robust yeast species for high level lipid production.
三酰甘油（TAGs）是有价值的多功能化合物，可作为营养和健康方面的代谢物，以及生物燃料生产的原料。尽管[具体微生物名称]是工业生产生化物质的理想微生物细胞工厂，但它不会大量产生脂质，TAGs仅占其细胞干重的约1%。在此，我们通过调控参与TAG合成和水解的脂滴相关蛋白，对[具体微生物名称]进行工程改造，以重新定向其代谢来过量生产TAGs。我们实施了一种推拉策略，过表达编码去调控的乙酰辅酶A羧化酶[具体酶名称]的基因，以及TAG形成的最后两步：磷脂酸磷酸酶（[具体酶名称]）和二酰甘油酰基转移酶（[具体酶名称]），最终导致TAGs产量达到129 mg∙gCDW。破坏TAG脂肪酶基因[具体基因名称]、[具体基因名称]、[具体基因名称]和甾醇酰基转移酶基因[具体基因名称]可将TAG含量提高到218 mg∙gCDW。通过缺失[具体基因名称]进一步破坏β-氧化，以及通过缺失[具体基因名称]利用3-磷酸甘油，均不影响TAGs水平。最后，破坏过氧化物酶体脂肪酰辅酶A转运蛋白[具体蛋白名称]导致积累254 mg∙gCDW。此处达到的TAG水平是[具体微生物名称]中报道的最高滴度，在含有2%葡萄糖的基本培养基中达到最大理论产量的27.4%。这项工作展示了使用一种工业上已确立且稳健的酵母物种进行高水平脂质生产的潜力。
