Siderotyping of Fluorescent Pseudomonads - Problems in the Determination of Molecular Masses by Mass Spectrometry

Species and even subspecies of fluorescent members of the Pseudomonadaceae can be identified by determining the nature of their main siderophores (iron chelating metabolites), the pyoverdins. This can be done by establishing their electrophoretic behavior and by uptake studies using 59Fe3+ labeled comparison compounds (“siderotyping”). Siderotyping requires a large collection of comparison material. Search could be facilitated and siderotyping results could be substantiated by a mass spectrometric determination of the molecular mass of the respective pyoverdin. Problems and strategies will be discussed.