Expressing a cytosolic pyruvate dehydrogenase complex to increase free fatty acid production in Saccharomyces cerevisiae
Artikel i vetenskaplig tidskrift, 2020

Background: Saccharomyces cerevisiae is being exploited as a cell factory to produce fatty acids and their derivatives as biofuels. Previous studies found that both precursor supply and fatty acid metabolism deregulation are essential for enhanced fatty acid synthesis. A bacterial pyruvate dehydrogenase (PDH) complex expressed in the yeast cytosol was reported to enable production of cytosolic acetyl-CoA with lower energy cost and no toxic intermediate. Results: Overexpression of the PDH complex significantly increased cell growth, ethanol consumption and reduced glycerol accumulation. Furthermore, to optimize the redox imbalance in production of fatty acids from glucose, two endogenous NAD+-dependent glycerol-3-phosphate dehydrogenases were deleted, and a heterologous NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase was introduced. The best fatty acid producing strain PDH7 with engineering of precursor and co-factor metabolism could produce 840.5 mg/L free fatty acids (FFAs) in shake flask, which was 83.2% higher than the control strain YJZ08. Profile analysis of free fatty acid suggested the cytosolic PDH complex mainly resulted in the increases of unsaturated fatty acids (C16:1 and C18:1). Conclusions: We demonstrated that cytosolic PDH pathway enabled more efficient acetyl-CoA provision with the lower ATP cost, and improved FFA production. Together with engineering of the redox factor rebalance, the cytosolic PDH pathway could achieve high level of FFA production at similar levels of other best acetyl-CoA producing pathways.

The pyruvate dehydrogenase complex

Free fatty acids

Redox factor

Saccharomyces cerevisiae

Författare

Yiming Zhang

Beijing University of Chemical Technology

Mo Su

Beijing University of Chemical Technology

Ning Qin

Beijing University of Chemical Technology

Jens B Nielsen

Beijing University of Chemical Technology

BioInnovation Institute

Chalmers, Biologi och bioteknik, Systembiologi

Zihe Liu

Beijing University of Chemical Technology

Microbial Cell Factories

1475-2859 (ISSN)

Vol. 19 1 226

Ämneskategorier

Biokemi och molekylärbiologi

Mikrobiologi

Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)

DOI

10.1186/s12934-020-01493-z

PubMed

33302960

Mer information

Senast uppdaterat

2020-12-21