Efficient Xylitol Production from Cornstalk Hydrolysate Using Engineered Escherichia coli Whole Cells

J Agric Food Chem. 2018 Dec 19;66(50):13209-13216. doi: 10.1021/acs.jafc.8b04666. Epub 2018 Dec 5.


Economic transformation of lignocellulose hydrolysate into valued-added products is of particular importance for energy and environmental issues. In this study, xylose reductase and glucose dehydrogenase were cloned into plasmid pETDuet-1 and then simultaneously expressed in Escherichia coli BL21(DE3), which was used as whole-cell catalyst for the first time to convert xylose into xylitol coupled with gluconate production. When tested with reconstituted xylose and glucose solution, 0.1 g/mL cells could convert 1 M xylose and 1 M glucose completely and produced 145.81 g/L xylitol with a yield of 0.97 (g/g) and 184.85 g/L gluconic acid with a yield of 1.03 (g/g) in 24 h. Subsequently, the engineered cells were applied in real cornstalk hydrolysate, which generated 30.88 g/L xylitol and 50.89 g/L gluconic acid. The cells were used without penetration treatment, and CaCO3 was used to effectively regulate the pH during the production, which further saved costs.

Keywords: cornstalk hydrolysate; glucose dehydrogenase; whole cell catalysis; xylitol; xylose reductase.

MeSH terms

  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Fermentation
  • Glucose / metabolism
  • Hydrolysis
  • Metabolic Engineering
  • Plant Stems / metabolism
  • Plant Stems / microbiology
  • Xylitol / biosynthesis*
  • Xylose / metabolism
  • Zea mays / metabolism
  • Zea mays / microbiology


  • Xylose
  • Glucose
  • Xylitol