The Phospholipid:Diacylglycerol Acyltransferase-Mediated Acyl-Coenzyme A-Independent Pathway Efficiently Diverts Fatty Acid Flux from Phospholipid into Triacylglycerol in Escherichia coli

• Published in: Applied and environmental microbiology 2020-09, Vol.86 (18)
• Main Authors: Wang, Lian, Jiang, Shan, Chen, Wen-Chao, Zhou, Xue-Rong, Huang, Ting-Xuan, Huang, Feng-Hong, Wan, Xia
• Format: Article
• Language: English
• Subjects: Accumulation; Acyl Coenzyme A - metabolism; Acyltransferase; Acyltransferases - metabolism; Cell growth; Coenzyme A; Derivatives; Diacylglycerol O-acyltransferase; Diglycerides; E coli; Escherichia coli; Escherichia coli - enzymology; Fatty acids; Fatty Acids - metabolism; Genetics and Molecular Biology; Lipase; Lipid metabolism; Metabolic Networks and Pathways; Microorganisms; Phospholipids; Phospholipids - metabolism; Supplements; Synergistic effect; Tags; Triglycerides; Triglycerides - metabolism
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.00999-20

Researchers have long endeavored to accumulate triacylglycerols (TAGs) or their derivatives in easily managed microbes. The attempted production of TAGs in has revealed barriers to the broad applications of this technology, including low TAG productivity and slow cell growth. We have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in mediated by phospholipid:diacylglycerol acyltransferase (CrPDAT) without interfering with membrane functions. We then showed the synergistic effect on TAG accumulation via the acyl-CoA-independent pathway mediated by PDAT and the acyl-CoA-dependent pathway mediated by wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT). Furthermore, CrPDAT led to synchronous TAG accumulation during cell growth, and this could be enhanced by supplementation of arbutin. We also showed that rationally mutated CrPDAT was capable of decreasing TAG lipase activity without impairing PDAT activity. Finally, ScPDAT from exhibited similar activities as CrPDAT in Our results suggest that the improvement in accumulation of TAGs and their derivatives can be achieved by fine-tuning of phospholipid metabolism in Understanding the roles of PDAT in the conversion of phospholipids into TAGs during the logarithmic growth phase may enable a novel strategy for the production of microbial oils. Although phospholipid:diacylglycerol acyltransferase (PDAT) activity is presumed to exist in prokaryotic oleaginous bacteria, the corresponding gene has not been identified yet. In this article, we have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in mediated by exogenous CrPDAT from without interfering with membrane functions. In addition, the acyl-CoA-independent pathway and the acyl-CoA-dependent pathway had the synergistic effect on TAG accumulation. Overexpression of led to synchronous TAG accumulation during cell growth. In particular, CrPDAT possessed multiple catalytic activities, and the rational mutation of CrPDAT led to the decrease of TAG lipase activity without impairing acyltransferase activity. The present findings suggested that applying PDAT in or other prokaryotic microbes may be a promising strategy for accumulation of TAGs and their derivatives.