Physicochemical characterization of the microbial Fe2+ chelator proferrorosamine from Pseudomonas roseus fluorescens.
The microbial chelating compound proferrorosamine A, produced by Pseudomonas roseus fluorescens, formed a complex with Fe2+ of which the apparent stability constant was found to be 10(23). The following order of increasing stability constants of metal complexes with proferrorosamine was established as: Ba2+, Ca2+, Mg2+, Mn2+ less than Hg2+ less than Zn2+ less than Pb2+ less than Co2+ less than Cu2+ congruent to Fe2+ less than Ni2+. Only Ni(2+)-proferrorosamine had a stability constant which was established as: Ba2+, Ca2+, Mg2+, Mn2+ less than Hg2+ less than Zn2+ less than Pb2+ less than Co2+ less than Cu2+ congruent to Fe2+ less than Ni2+. Only Ni(2+)-proferrorosamine had a stability constant which was ca 32 times higher than Fe(2+)-proferrorosamine. Because of the production of proferrorosamine the growth of Ps. roseus fluorescens was not inhibited in iron limiting media by the addition of 0.15 mmol/l of the weaker chemical Fe2+ chelator 2,2'-dipyridyl. This contrasted with the proferrorosamine-negative mutant K2 and Ps. stutzeri, which only produces Fe(3+)-chelating siderophores. Furthermore, it was found that proferrorosamine was able to dissolve Fe2+ from stainless steel. These results show that proferrorosamine is a strong and selective Fe2+ chelator which could be used as an alternative for the toxic 2,2'-dipyridyl to control lactic acid fermentations.
Vande Woestyne
M
M
Laboratorium of Microbial Ecology, Faculty of Agricultural Sciences, State University of Gent, Belgium.
Bruyneel
B
B
Verstraete
W
W
D015082:2,2'-Dipyridyl / Q000494:pharmacology; D003343:Corrosion; D007502:Iron Chelating Agents / Q000737:chemistry*; D011549:Pseudomonas; D011758:Pyrroles / Q000737:chemistry*; D012995:Solubility; D013053:Spectrophotometry; D013193:Stainless Steel / Q000737:chemistry
D007502:Iron Chelating Agents; D011758:Pyrroles; D013193:Stainless Steel; C002210:proferrorosamine A; D015082:2,2'-Dipyridyl