Mutagenicity testing with Salmonella typhimurium strains. II. The effect of unusual phenotypes on the mutagenic response.

The enhanced sensitivity of some Salmonella typhimurium strains to the mutagenic action of a number of chemicals appears to be due to the defect in the uvrB gene product and not to an inability to produce H-2-S or to the absence of formic acid hydrogenlyase which also characterizes these strains.