title: Respiration-deficient mutants of Zymomonas mobilis show improved growth and ethanol fermentation under aerobic and high temperature conditions.
abstract: Respiration-deficient mutant (RDM) strains of Zymomonas mobilis were isolated from antibiotic-resistant mutants. These RDM strains showed various degrees of respiratory deficiency. All RDM strains exhibited much higher ethanol fermentation capacity than the wild-type strain under aerobic conditions. The strains also gained thermotolerance and exhibited greater ethanol production at high temperature (39°C), under both non-aerobic and aerobic conditions, compared with the wild-type strain. Microarray and subsequent quantitative PCR analyses suggest that enhanced gene expression involved in the metabolism of glucose to ethanol resulted in the high ethanol production of RDM strains under aerobic growth conditions. Reduction of intracellular oxidative stress may also result in improved ethanol fermentation by RDM strains at high temperatures.
authors.affiliation: Department of Food and Fermentation Science, Beppu University, Kitaishigaki 82, Beppu, Oita 874-8501, Japan. hayashi@nm.beppu-u.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Furuta
authors.forename: Kensuke
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D000332:Aerobiosis; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006358:Hot Temperature; D009154:Mutation; D017355:Zymomonas / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000431:Ethanol; D005947:Glucose