Effects of iron level on the antagonistic action of siderophores from non-pathogenic Staphylococcus spp.

The production, detection and the effects of iron concentration on the siderophore production of Staphylococcus strains used as meat starter cultures were studied. Non-pathogenic Staphylococcus strains produce extracellular low molecular weight compounds which exhibited positive reactivity when measured by a universal detection method for siderophores. The production of siderophores was very closely associated with the iron concentration in the medium, and very low additions considerably reduced siderophore production. Although the production of siderophores was highly iron-dependent, the antimicrobial activity of spent medium from Staphylococcus cultures against selected yeasts and moulds remained considerable under high iron concentrations.