Synergistic killing of Escherichia coli by near-UV radiation and hydrogen peroxide: distinction between recA-repairable and recA-nonrepairable damage.

AUTOR(ES)

Hartman, P S

RESUMO

Wild-type cells and six DNA repair-deficient mutants (lexA, recA, recB, recA, recB, polA1, and uvrA) of Escherichia coli K-12 were treated with near-ultraviolet radiation plus hydrogen peroxide (H2O2). At low H2O2 concentrations (6 X 10(-6) to 6 X 10(-4) M), synergistic killing occurred in all strains except those containing a mutation in recA. This RecA-repairable damage was absent from stationary-phase cells but increased in logarithmic cells as a function of growth rate. At higher H2O2 concentrations (above 6 X 10(-4) M) plus near-ultraviolet radiation, all strains, including those with a mutation in recA, were synergistically killed; thus, at high H2O2 concentrations, the damage was not RecA repairable.

Documentos Relacionados

• Escherichia coli xthA mutants are sensitive to inactivation by broad-spectrum near-UV (300- to 400-nm) radiation.
• Effect of near-UV light on Escherichia coli in the presence of 8-methoxypsoralen: wavelength dependency of killing, induction of prophage, and mutation.
• Near-UV mutagenesis: photoreactivation of 365-nm-induced mutational lesions in Escherichia coli WP2s.
• Control of sensitivity to inactivation by H2O2 and broad-spectrum near-UV radiation by the Escherichia coli katF locus.
• Repair response of Escherichia coli to hydrogen peroxide DNA damage.