Enhanced protopanaxadiol production from xylose by engineered Yarrowia lipolytica

Microbial Cell Factories

Shuo Xu¹  Yufen Wu¹  Dashuai Li¹  Xiao Gao¹  Man Li¹  Wenyu Lu¹ 

[1] 0000 0004 1761 2484, grid.33763.32, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People’s Republic of China;0000 0004 0369 313X, grid.419897.a, Key Laboratory of System Bioengineering (Tianjin University), Ministry of Education, Tianjin, People’s Republic of China;0000 0004 1761 2484, grid.33763.32, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People’s Republic of China;

关键词: Protopanaxadiol;    Xylose;    Yarrowia lipolytica;    Metabolic engineering;    Synthetic biology;   

DOI  :  10.1186/s12934-019-1136-7

来源: publisher

【 摘 要 】

BackgroundAs renewable biomass, lignocellulose remains one of the major choices for most countries in tackling global energy shortage and environment pollution. Efficient utilization of xylose, an important monosaccharide in lignocellulose, is essential for the production of high-value compounds, such as ethanol, lipids, and isoprenoids. Protopanaxadiol (PPD), a kind of isoprenoids, has important medical values and great market potential.ResultsThe engineered protopanaxadiol-producing Yarrowia lipolytica strain, which can use xylose as the sole carbon source, was constructed by introducing xylose reductase (XR) and xylitol dehydrogenase (XDH) from Scheffersomyces stipitis, overexpressing endogenous xylulose kinase (ylXKS) and heterologous PPD synthetic modules, and then 18.18 mg/L of PPD was obtained. Metabolic engineering strategies such as regulating cofactor balance, enhancing precursor flux, and improving xylose metabolism rate via XR (K270R/N272D) mutation, the overexpression of tHMG1/ERG9/ERG20 and transaldolase (TAL)/transketolase (TKL)/xylose transporter (TX), were implemented to enhance PPD production. The final Y14 strain exhibited the greatest PPD titer from xylose by fed-batch fermentation in a 5-L fermenter, reaching 300.63 mg/L [yield, 2.505 mg/g (sugar); productivity, 2.505 mg/L/h], which was significantly higher than the titer of glucose fermentation [titer, 167.17 mg/L; yield, 1.194 mg/g (sugar); productivity, 1.548 mg/L/h].ConclusionThe results showed that xylose was more suitable for PPD synthesis than glucose due to the enhanced carbon flux towards acetyl-CoA, the precursor for PPD biosynthetic pathway. This is the first report to produce PPD in Y. lipolytica with xylose as the sole carbon source, which developed a promising strategy for the efficient production of high-value triterpenoid compounds.

【 授权许可】

CC BY