文献类型：期刊文献

英文题名：Enhanced squalene biosynthesis in Yarrowia lipolytica based on metabolically engineered acetyl-CoA metabolism

作者：Huang, Yu-Ying[1];Jian, Xing-Xing[1];Lv, Yu-Bei[1];Nian, Ke-Qing[1];Gao, Qi[1];Chen, Jun[1];Wei, Liu-Jing[1];Hua, Qiang[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Shanghai Collaborat Innovat Ctr Biomfg Technol, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2018

卷号：281

起止页码：106

外文期刊名：JOURNAL OF BIOTECHNOLOGY

收录：;EI(收录号：20182805527537);WOS:【SCI-EXPANDED(收录号:WOS:000440561500013)】；

基金：This study was financially supported by National Natural Science Foundation of China (21776081, 21576089) and Natural Science Foundation of Shanghai (18ZR1410000).

语种：英文

外文关键词：Yarrowia lipolytica; Acetyl-CoA; Squalene; Metabolic network model; Terpenoid

摘要：As a bioactive triterpenoid, squalene is widely used in the food industry, cosmetics, and pharmacology. Squalene's major commercial sources are the liver oil of deep-sea sharks and plant oils. In this study, we focused on the enhancement of squalene biosynthesis in Yarrowia lipolytica, with particular attention to the engineering of acetyl-CoA metabolism based on genome-scale metabolic reaction network analysis. Although the overexpression of the rate-limiting endogenous ylHMG1 (3-hydroxy-3-methylglutaryl-CoA reductase gene) could improve squalene synthesis by 3.2-fold over that by the control strain, the availability of the key intracellular precursor, acetyl-CoA, was found to play a more significant role in elevating squalene production. Analysis of metabolic networks with the newly constructed genome-scale metabolic model of Y. lipolytica iYL_2.0 showed that the acetyl-CoA pool size could be increased by redirecting carbon flux of pyruvate dehydrogenation towards the ligation of acetate and CoA or the cleavage of citrate to form oxaloacetate and acetyl-CoA. The overexpression of either acetyl-CoA synthetase gene from Salmonella enterica (acs*) or the endogenous ATP citrate lyase gene (ylACL1) resulted in a more than 50% increase in the cytosolic acetyl-CoA level. Moreover, iterative chromosomal integration of the ylHMG1, asc*, and ylACL1 genes resulted in a significant improvement in squalene production (16.4-fold increase in squalene content over that in the control strain). We also found that supplementation with 10mM citrate in a flask culture further enhanced squalene production to 10 mg/g DCW. The information obtained in this study demonstrates that rationally engineering acetyl-CoA metabolism to ensure the supply of this key metabolic precursor is an efficient strategy for the enhancement of squalene biosynthesis.