PURIFICATION OF YERSINIABACTIN - A SIDEROPHORE AND POSSIBLE VIRULENCEFACTOR OF YERSINIA-ENTEROCOLITICA

HPLC analysis revealed that Yersinia enterocolitica WA-C produced two substances under iron-limiting conditions one of which was identified as 2,3-dihydroxybenzoyl-L-serine. The other compound had iron-complexi ng activity and was called yersiniabactin. The fur mutant H1852 was sh own to produce yersiniabactin constitutively in an iron-independent ma nner. Yersiniabactin was isolated by ethyl acetate extraction from the spent medium of H1852, size-fractionation chromatography and preparat ive HPLC. A catechol function was demonstrated with different chemical assays and by UV-visible spectroscopy. The molecular mass of yersinia bactin was determined to be 482 Da. Purified yersiniabactin stimulated growth of Y. enterocolitica and Escherichia coli phi under iron-limit ing conditions and apparently served as an iron carrier. Transport of Fe-55-yersiniabactin was TonB-dependent, indicating a receptor-mediate d uptake across the outer membrane. A pesticin-resistant mutant missin g the receptor protein FyuA was unable to transport and use yersiniaba ctin as a siderophore.