CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
SYNERGISTIC EFFECT OF FLAVONOIDS ON THE VIABILITY OF Escherichia coli
RODRIGUEZ VAQUERO M. J; MANCA DE NADRA M. C.
Año: 2007 vol. 31 p. 302 - 302
The aim of this work was to investigate and compare the combined effect of mixtures of flavonoids quercetin, rutin and catechin, in equal final concentration on the viability of Escherichia coli ATCC 35218, a bacterium that may cause human infections. Growth experiments were performed in nutrient broth and agar medium. Phenolic compounds were added to the medium of two and three, to obtain a concentration of 100 mg/l. The media were inoculated at 7% with overnight culture. Bacterial growth was followed by incubation for 18h at 30ºC in a tunable microplate reader. The plates used were microtitre plate flat form. The cultures were agitated each five minutes. Bacterial growth measurement was determined indirectly by measuring absorbance at 560 nm by the microplate reader and directly by enumerating the number of viable cells by plating serial dilutions in the Nutrient agar medium. The results showed a synergistic effect of cellular death that increased from 1 to 1.8 logarithmic cycles for the combinations of rutin-catechin, quercetin-catechin and quercetin-rutin. The greater inhibition effect was observed with the combination of three flavonoids compounds that increased 2 logarithmic cycles in the death of Escherichia coli. Our results confirm the importance of knowing the composition and concentration flavonoids compounds in these products.