INVESTIGADORES
CORBALAN Natalia Soledad
congresos y reuniones científicas
Título:
OXIDATIVE STRESS PREVENTS COLONY FORMATION IN AN IMPAIRED IN CATECHOLS SYNTHESIS Escherichia coli
Autor/es:
PERALTA D; ADLER, CONRADO; CORBALÁN NATALIA S.; POMARES, MARÍA FERNANDA; VINCENT ,PAULA A.
Reunión:
Congreso; 48 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2012
Resumen:
Under iron-limited conditions, produces the
catecholate siderophore enterobactin. We proposed that
enterobactin has a new role as an intracellular protector against
oxidative stress. We also showed that an impaired in
enterobactin synthesis ( ) is unable to develop colonies on solid
M9 medium. Iron supplementation did not recover colony
formation, indicating that this phenotype is not due to iron
deficiency. It is known that the viable but non-culturable phenotype
is associated to oxidative stress. As we propose that catechols may
act as radical scavengers, the absence of colonies in an mutant
context could be related with an increment in the oxidative stress.
Comparing with the wild type strain, the mutant showed
greater sensitivity to hydrogen peroxide, paraquat and antibiotics
which promote reactive oxygen species. The double mutant
displayed a pronounced colony impairment phenotype and
were more sensitive to the agents tested. Finally, we observed that a
normal growth was achieved when ascorbic acid was added to the
medium or when the mentioned strains were grown in anaerobiosis.
Results suggest that the incapacity to form colonies could be due to
hostile conditions caused by oxidative stress and support our
hypothesis implying cathecols siderophores in a oxidative stress
protection function.