title: Glycerol elicits energy taxis of Escherichia coli and Salmonella typhimurium.
abstract: Escherichia coli and Salmonella typhimurium show positive chemotaxis to glycerol, a chemical previously reported to be a repellent for E. coli. The threshold of the attractant response in both species was 10(-6) M glycerol. Glycerol chemotaxis was energy dependent and coincident with an increase in membrane potential. Metabolism of glycerol was required for chemotaxis, and when lactate was present to maintain energy production in the absence of glycerol, the increases in membrane potential and chemotactic response upon addition of glycerol were abolished. Methylation of a chemotaxis receptor was not required for positive glycerol chemotaxis in E. coli or S. typhimurium but is involved in the negative chemotaxis of E. coli to high concentrations of glycerol. We propose that positive chemotaxis to glycerol in E. coli and S. typhimurium is an example of energy taxis mediated via a signal transduction pathway that responds to changes in the cellular energy level.
authors.affiliation: Department of Microbiology and Molecular Genetics, Loma Linda University, California 92350, USA.
authors.forename: I B
authors.initials: IB
authors.lastname: Zhulin
authors.forename: E H
authors.initials: EH
authors.lastname: Rowsell
authors.forename: M S
authors.initials: MS
authors.lastname: Johnson
authors.forename: B L
authors.initials: BL
authors.lastname: Taylor
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002630:Chemotactic Factors / Q000235:genetics; D002633:Chemotaxis / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D005990:Glycerol / Q000378:metabolism / Q000494:pharmacology*; D008565:Membrane Proteins / Q000172:deficiency; D000072236:Methyl-Accepting Chemotaxis Proteins; D009154:Mutation; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D002630:Chemotactic Factors; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C069656:CheB protein, Bacteria; D005990:Glycerol