CINDECA   05422
CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
artículos
Título:
Culturability and viability of Salmonella typhimurium during photo-Fenton process at pH 5.5 under solar simulated irradiation.
Autor/es:
JULIÁN ANDRES RENGIFO HERRERA; OLGA LUCIA CASTAÑO; JANETH SANABRIA
Revista:
Journal of Water Resource and Protection
Editorial:
Scientific Research Publishing
Referencias:
Año: 2013 vol. 5 p. 21 - 27
ISSN:
1945-3094
Resumen:
Culturability and viability techniques such as
plate count on solid agar (PC), Most Probable Number (MPN) and Direct Viable
Count-Fluorescence In Situ
Hybridation (DVC FISH) were used to study the inactivation of Salmonella typhimurium by photo-Fenton
process at pH 5.5.
In the presence of only simulated solar
irradiation (500 W m-2), S.
typhimurim showed that both culturability measured by MPN and viability
(measured by DVC FISH) underwent just a slight decreasing of 2 and 1 log
respectively after 240 min of light exposition while culturability measured by
PC did not show any change. Results after 48 h of dark conditions did not
reveal re-growth. However, when experiment was carried out in the presence of 2
mg L-1 of Fe3+ and 20 mg L-1 of H2O2
and pH 5.5, culturability was strongly affected after 240 min of simulated
solar irradiation; nevertheless, viability was only slightly altered (~1 log).
During dark period of 48 h changes on culturability and viability were not
observed.
On the other hand, it was also found that sugar
metabolism was affected rather the amino-acids in S. typhimurium cells irradiated at different times upon
photo-Fenton conditions. These findings might suggest for the first time that
photo-Fenton process at pH 5.5 could induce viable but nonculturable state
(VBNC) on waterborne S. typhimurium
and that probably sugar metabolism damage could activate the VBNC state.