title: Comparison of glucose/xylose co-fermentation by recombinant Zymomonas mobilis under different genetic and environmental conditions.
abstract: Three xylose-fermenting recombinant Zymomonas mobilis strains containing different Peno-talB/tktA operon terminators were engineered. Each showed similar levels of foreign protein expression and xylose fermentation performance. Strain CP4-P2-1 was further used to compare the glucose/xylose co-fermentation under various cultivation environments to improve the efficiency of the process. Optimal co-fermentation was achieved at 30-34 °C and pH 5.5 using xylose-grown preculture cells giving 20.5 g ethanol/l, ethanol productivity of 0.43 g/l h and ethanol yield of 0.44 g/g at 48 h. Adverse culture conditions mainly influenced the efficiency of xylose fermentation but not glucose fermentation. The key factors affecting co-fermentation were also explored at the molecular level. This study provides valuable insights into the effective harnessing of biomass resources.
authors.affiliation: Tianjin University, R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Huina
authors.initials: H
authors.lastname: Dong
authors.forename: Shaolan
authors.initials: S
authors.lastname: Zou
authors.forename: Jiefang
authors.initials: J
authors.lastname: Hong
authors.forename: Minhua
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways / Q000235:genetics; D013696:Temperature; D014994:Xylose / Q000378:metabolism*; D017355:Zymomonas / Q000235:genetics / Q000378:metabolism*
chemical_list: D000431:Ethanol; D014994:Xylose; D005947:Glucose