Measurement of sensitivity to H₂O₂ stress by disc inhibition assay (procedure described in Materials and Methods).

<p>(A) Phenotype of the wild-type (resistant), the <i>katA</i> mutant (highly sensitive), and the <i>DR0265</i> mutant (middle sensitive) are shown. (B) The mutants are classified into four categories depending on the diameter (in mm) of growth inhibition area as indicated.