INVESTIGADORES
ADLER Conrado
congresos y reuniones científicas
Título:
Pyochelin has antibiotic activity against Xanthomonas axonopodis pv. citri
Autor/es:
ADLER CONRADO; SEYEDSAYAMDOST; KOLTER,R; VINCENT PAULA
Lugar:
San Miguel de Tucumán
Reunión:
Congreso; SAIB; 2009
Institución organizadora:
SAIB
Resumen:
Using a screening method for finding active antibiotics against
Xanthomonas axonopodis pv.citri (citrus canker agent), we isolated
a bacterial strain capable of inhibiting this plant pathogen growth.
After sequencing 16S rDNA and analyzing it using BLAST, we
were able to determine genus and speciation. The producing strain,
identified as Pseudomonas aeruginosa, secreted the active
compound to the supernatant during stationary phase, and its
production was prevented if iron was added into the culture
medium. In order to purify the compound, the supernatant of a
stationary phase culture was run through a C18 cartridge and
fractions with different methanol/water solutions were collected.
The 40% fraction containing the active compound was analyzed
with a LC/MS. The UV spectrum and mass data (324Da)
corresponded with the siderophore pyochelin. After HPLC
purification using a 40-100% Acetonitrile/water 0.1% formic acid,
NMR analysis confirmed the chemical nature of the siderophore.
Even though there is literature evidence of siderophore
interchangeability, pyochelin is acting in our assays as an
antimicrobial in an iron-independent manner. The action
mechanism, as an antimicrobial agent, and uptake-efflux
transporters involved are part of our research goals. This represents
an important finding due to the potential use of pyochelin producing bacteria in citrus canker biocontrol.