Salmonella typhimurium was shown to use the gentisate pathway to metabolize m-hydroxybenzoate and gentisate, m-Hydroxybenzoate hydroxylase and gentisate 1,2-dioxygenase were induced by growth on either gentisate or m-hydroxybenzoate. These enzymes were not detected when the bacteria were grown with glucose or glucose and either m-hydroxybenzoate or gentisate. However, both enzymes were induced when the bacteria were grown on succinate with either substrate. The maleylpyruvate isomerase required reduced glutathione and was irreversibly inhibited by N-ethylmaleimide.