TonB-dependent iron supply in Salmonella by alpha-ketoacids and alpha-hydroxyacids

FEMS Microbiol Lett. 1996 Jun 15;140(1):65-70. doi: 10.1111/j.1574-6968.1996.tb08316.x.


A range of structurally diverse alpha-ketoacids and alpha-hydroxyacids promoted the growth of isolates of Salmonella serovars S. typhimurium, S. enteritidis, S. agona, S. paratyphi and S. stanleyville in iron restricted conditions in the absence of functional siderophores. Growth stimulation, observed both in cross-feeding tests on solid medium and in liquid cultures, and uptake of 55Fe in the presence of alpha-ketoisocaproic acid, were TonB dependent in S. typhimurium. In this respect the mechanism is distinct from a previously described Serratia marcescens system (sfuABC); the presence of the cloned sfuABC genes mediated tonB-independent uptake by S. typhimurium of iron complexed with alpha-ketoacids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology*
  • Bacteriological Techniques
  • Biological Transport / drug effects
  • Biological Transport / physiology
  • Cell Division / drug effects
  • Hydroxy Acids / pharmacology*
  • Iron / metabolism*
  • Keto Acids / pharmacology*
  • Membrane Proteins / physiology*
  • Salmonella / growth & development
  • Salmonella / metabolism*
  • Salmonella enteritidis / cytology
  • Salmonella enteritidis / metabolism
  • Salmonella paratyphi A / cytology
  • Salmonella paratyphi A / metabolism
  • Salmonella typhimurium / cytology
  • Salmonella typhimurium / metabolism
  • Siderophores / physiology


  • Bacterial Proteins
  • Hydroxy Acids
  • Keto Acids
  • Membrane Proteins
  • Siderophores
  • tonB protein, Bacteria
  • Iron