FLUORESCENT SIDEROPHORE PRODUCED BY A NONIL PHENOL DEGRADING Ochrobactrum sp

LOZADA, MARIANA; JARES-ERIJMAN, ELIZABETH; ERIJMAN, LEONARDO

Córdoba, Argentina

Congreso; Congreso de la Sociedad Argentina de Investigaciones Bioquímicas (SAIB); 2001

Sociedad Argentina de Investigaciones Bioquímicas

Nonylphenol (NP) is an ubiquitous pollutant originatcd from partial degradalion of nonylphenol ethoxylates, a comercially important nonionic surfactant. NP possesses estrogen-mimicking effects that have been linked to the observed decline of reproductive health in aquatic environments. Using conventional enrichment techniques we llave isolated a bacterial strain able to grow on nonylphenol as only carbon and energy source. From the information obtained using a polyphasic taxonomic approach, including 16S rRNA sequencing REP-PCR genotyping, total protein analysis, C source utilization and antibiotic sensitivity, it was determined that the isolate belongs to the genus Ochrobactrum. While characterizing the phylogenetical affiliation of the isolate, we observed that the colonies growing aerobically on LB solid media secreted a blue substance. Cultures grown on liquid media failed to result in the elaboration of the siderophore-like activity.The colored cumpound was extracted from LB agar plates with methylene chloride and purified using a selective extraction method by taking advantage of the changes in solubility properties upon complexation of Fe3+. Structure elucidation of the non-proteinaceous iron chelator was performed by spectroscopical (one and two dimensional NMR, mass spectrometry, IR, UV and fluorescence) and chemical methods. The specific response to submicromolar concentrations of Fe3+ and Fe2+, revealed as dramatic changes in absorption ano fluorescence, even in the presence of Ca2+, Mg2+,Na+ and K +, makes the cumpound a suitable candidate as a highly selective Fe3+/Fe3+ sensor.