Recycling Carbon Dioxide during Xylose Fermentation by Engineered Saccharomyces cerevisiae

ACS Synth Biol. 2017 Feb 17;6(2):276-283. doi: 10.1021/acssynbio.6b00167. Epub 2016 Oct 31.


Global climate change caused by the emission of anthropogenic greenhouse gases (GHGs) is a grand challenge to humanity. To alleviate the trend, the consumption of fossil fuels needs to be largely reduced and alternative energy technologies capable of controlling GHG emissions are anticipated. In this study, we introduced a synthetic reductive pentose phosphate pathway (rPPP) into a xylose-fermenting Saccharomyces cerevisiae strain SR8 to achieve simultaneous lignocellulosic bioethanol production and carbon dioxide recycling. Specifically, ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum and phosphoribulokinase from Spinacia oleracea were introduced into the SR8 strain. The resulting strain with the synthetic rPPP was able to exhibit a higher yield of ethanol and lower yields of byproducts (xylitol and glycerol) than a control strain. In addition, the reduced release of carbon dioxide by the engineered strain was observed during xylose fermentation, suggesting that the carbon dioxide generated by pyruvate decarboxylase was partially reassimilated through the synthetic rPPP. These results demonstrated that recycling of carbon dioxide from the ethanol fermentation pathway in yeast can be achieved during lignocellulosic bioethanol production through a synthetic carbon conservative metabolic pathway. This strategy has a great potential to alleviate GHG emissions during the production of second-generation ethanol.

Keywords: CO2 recycling; Saccharomyces cerevisiae; bioethanol; carbon conservation.

MeSH terms

  • Carbon Dioxide / metabolism*
  • Climate Change
  • Ethanol / metabolism
  • Fermentation / physiology*
  • Genetic Engineering / methods
  • Glucose / metabolism
  • Glycerol / metabolism
  • Metabolic Networks and Pathways / physiology
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Pyruvate Decarboxylase / metabolism
  • Ribulosephosphates / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Xylitol / metabolism
  • Xylose / metabolism*


  • Ribulosephosphates
  • Saccharomyces cerevisiae Proteins
  • Carbon Dioxide
  • ribulose-1,5 diphosphate
  • Ethanol
  • Xylose
  • Phosphotransferases (Alcohol Group Acceptor)
  • phosphoribulokinase
  • Pyruvate Decarboxylase
  • Glucose
  • Glycerol
  • Xylitol