coprogen and fusigen

Due to the necessity of iron for housekeeping functions, nutrition, morphogenesis and secondary metabolite production, siderophore piracy could be a key strategy in soil and substrate colonization by microorganisms. Here we report that mutants of bacterium Streptomyces coelicolor unable to produce desferrioxamine siderophores could recover growth when the plates were contaminated by indoor air spores of a Penicillium species and Engyodontium album. UPLC-ESI-MS analysis revealed that the HPLC fractions with the extracellular 'resuscitation' factors of the Penicillium isolate were only those that contained siderophores, i.e. Fe-dimerum acid, ferrichrome, fusarinine C and coprogen. The restored growth of the Streptomyces mutants devoid of desferrioxamine is most likely mediated through xenosiderophore uptake as the cultivability depends on the gene encoding the ABC-transporter-associated DesE siderophore-binding protein. That a filamentous fungus allows the growth of desferrioxamine non-producing Streptomyces in cocultures confirms that xenosiderophore piracy plays a vital role in nutritional interactions between these taxonomically unrelated filamentous microorganisms.

Topics: Ascomycota; ATP-Binding Cassette Transporters; Deferoxamine; Ferric Compounds; Hydroxamic Acids; Iron; Penicillium; Siderophores; Streptomyces coelicolor

A screening for siderophores produced by the ectomycorrhizal fungi Laccaria laccata and Laccaria bicolor in synthetic low iron medium revealed the release of several different hydroxamate siderophores of which four major siderophores could be identified by high resolution mass spectrometry. While ferricrocin, coprogen and triacetylfusarinine C were assigned as well as other known fungal siderophores, a major peak of the siderophore mixture revealed an average molecular mass of 797 for the iron-loaded compound. High resolution mass spectrometry indicated an absolute mass of m/z = 798.30973 ([M + H](+)). With a relative error of Δ = 0.56 ppm this corresponds to linear fusigen (C33H52N6O13Fe; MW = 797.3). The production of large amounts of linear fusigen by these basidiomycetous mycorrhizal fungi may possibly explain the observed suppression of plant pathogenic Fusarium species. For comparative purposes Fusarium roseum was included in this study as a well known producer of cyclic and linear fusigen.

Topics: Antibiosis; Chromatography, High Pressure Liquid; Culture Media; Ferric Compounds; Ferrichrome; Fusarium; Hydroxamic Acids; Iron; Laccaria; Mass Spectrometry; Molecular Weight; Plant Roots; Siderophores; Tracheophyta

The behaviour of a series of hydroxamate siderophores--microbially produced iron complexes - was investigated using electrospray ionisation mass spectrometry (ESI-MS). Three groups of iron hydroxamate siderophores, namely the ferrioxamines, ferrichromes and coprogens/fusigens, were separated by high-performance liquid chromatography (HPLC) prior to ESI and MS(2) fragmentation. For the majority of the siderophores, both protonated molecules and sodium adducts were observed. The most abundant ion was selected for collision-induced fragmentation. Potential fragmentation mechanisms are postulated and discussed. Fragmentation patterns differed between siderophore groups; however, common fragmentation patterns were observed for siderophore ions within the groups examined. Cleavage frequently occurred at carbon-nitrogen or carbon-oxygen bonds. Fragmentation of the ions also involved cleavage of iron-oxygen bonds and transfer of the charge to iron.

Topics: Ferric Compounds; Ferrichrome; Hydroxamic Acids; Mass Spectrometry; Molecular Structure; Molecular Weight; Reference Standards; Reproducibility of Results; Siderophores; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Three strains of the fungus Aspergillus, Aspergillus quadricinctus (E. Yuill), A. fumigatus (Fresenius), and A. melleus (Yukawa), each producing different iron-chelating compounds during iron-deficient cultivation, were used for 55Fe3+ uptake measurements. Iron from chelates of the ferrichrome-type family was taken up by young mycelia of all strains tested, irrespective of the ferrichrome-type compound these strains predominantly produce in low-iron cultures. Ferrichrysin-producing strains, however, seem to favor ferrichrysin iron uptake, whereas ferrichrome, ferricrocin, and even ferrirubin showed similar iron transport properties in all of these strains. Compared to iron uptake from ferrichrome-type compounds (Km approximately 4 uM) iron uptake from fusigen revealed completely different kinetic values (Km approximately 50 to 80 muM). Iron from exogenous chelates, e.g., from coprogen produced by Neurospora crassa for ferrioxamine B produced by Streptomyces pilosus, can obviously not be taken up by Aspergillus, confirming the pronounced specificity of chelate-iron transport in fungi.

Topics: Aspergillus; Aspergillus fumigatus; Azides; Biological Transport, Active; Ferric Compounds; Ferrichrome; Hydroxamic Acids; Iron; Iron Chelating Agents; Kinetics; Species Specificity