title: Identification of erythrobactin, a hydroxamate-type siderophore produced by Saccharopolyspora erythraea.
abstract: OBJECTIVE
  To investigate the production of siderophores by Saccharopolyspora erythraea SGT2 and how this production is affected by the inoculum.
  
  
  RESULTS
  When grown in a low-iron, chemically defined medium (CDM), the soil dwelling actinomycete S. erythraea secretes a substance that is reactive in the nonspecific chrome azurol S (CAS) assay. Importantly, the production of CAS-reactive substance is highly reduced upon the addition of 0.925 micromol l(-1) iron to the cultures and has a peak of production in the late-log to early stationary growth phase. In addition, the culture supernatants tested were negative in the Arnow and Rioux assays but positive in the Csáky procedure. Interestingly, we also found evidence that the production of this CAS-reactive substance in CDM was highly reduced, when inoculated with cells that had been previously grown to late-stationary phase. Conversely, inocula derived from late-log to early stationary cultures presented high levels of CAS activity.
  
  
  CONCLUSIONS
  These results indicate that S. erythraea produces a hydroxamate-type siderophore that we have generically designated as erythrobactin. Additionally, the inocula growth stage plays a key role in siderophore production in S. erythraea.
  
  
  CONCLUSIONS
  It is the first evidence for siderophore synthesis in S. erythraea and one of the first examples of non-polyketide secondary metabolite production by this organism.
authors.affiliation: Department of Biochemical Engineering, Advanced Centre for Biochemical Engineering, University College London, London, UK.
authors.forename: P H
authors.initials: PH
authors.lastname: Oliveira
authors.forename: A
authors.initials: A
authors.lastname: Batagov
authors.forename: J
authors.initials: J
authors.lastname: Ward
authors.forename: F
authors.initials: F
authors.lastname: Baganz
authors.forename: P
authors.initials: P
authors.lastname: Krabben
mesh_terms: D003470:Culture Media; D006877:Hydroxamic Acids / Q000302:isolation & purification; D062385:Hydroxybenzoates; D016930:Saccharopolyspora / Q000254:growth & development / Q000378:metabolism*; D017262:Siderophores / Q000302:isolation & purification*
chemical_list: D003470:Culture Media; D006877:Hydroxamic Acids; D062385:Hydroxybenzoates; D017262:Siderophores; C015076:chrome azurol S