Increasing lipid yield in Yarrowia lipolytica through phosphoketolase and phosphotransacetylase expression in a phosphofructokinase deletion strain

Biotechnology for Biofuels

A. Joe Shaw¹  Annapurna Kamineni²  Gamuchirai Chifamba²  Shuyan Chen²  Andrew L. Consiglio²  Kyle MacEwen²  Vasiliki Tsakraklides² 

[1] Belmont, Massachusetts, United States;Ginkgo Bioworks, 27 Drydock Ave, Boston, Massachusetts, United States;

关键词: Phosphotransacetylase;    Phosphoketolase;    Lipid yield;    Cell-specific lipid productivity;    Yarrowia lipolytica;    Central carbon metabolism;   

DOI  :  10.1186/s13068-021-01962-6

来源: Springer

【 摘 要 】

BackgroundLipids are important precursors in the biofuel and oleochemical industries. Yarrowia lipolytica is among the most extensively studied oleaginous microorganisms and has been a focus of metabolic engineering to improve lipid production. Yield improvement, through rewiring of the central carbon metabolism of Y. lipolytica from glucose to the lipid precursor acetyl-CoA, is a key strategy for achieving commercial success in this organism.ResultsBuilding on YB-392, a Y. lipolytica isolate known for stable non-hyphal growth and low citrate production with demonstrated potential for high lipid accumulation, we assembled a heterologous pathway that redirects carbon flux from glucose through the pentose phosphate pathway (PPP) to acetyl-CoA. We used phosphofructokinase (Pfk) deletion to block glycolysis and expressed two non-native enzymes, phosphoketolase (Xpk) and phosphotransacetylase (Pta), to convert PPP-produced xylulose-5-P to acetyl-CoA. Introduction of the pathway in a pfk deletion strain that is unable to grow and accumulate lipid from glucose in defined media ensured maximal redirection of carbon flux through Xpk/Pta. Expression of Xpk and Pta restored growth and lipid production from glucose. In 1-L bioreactors, the engineered strains recorded improved lipid yield and cell-specific productivity by up to 19 and 78%, respectively.ConclusionsYields and cell-specific productivities are important bioprocess parameters for large-scale lipid fermentations. Improving these parameters by engineering the Xpk/Pta pathway is an important step towards developing Y. lipolytica as an industrially preferred microbial biocatalyst for lipid production.

【 授权许可】

CC BY