FIG. 2.

Comparison of the toxicities of As(III) and Sb(III) to the wild-type A. tumefaciens strain 5A. Toxicity was estimated by growth response. Cells were first cultured in minimal mannitol ammonium broth in the presence (preexposed) or absence (naïve) of 50 μM As(III) or Sb(III) and then inoculated into the same medium amended with or without 50 μM As(III) or Sb(III). □, As-naïve strain 5A grown in the absence of 50 μM As(III); ▪, As-naïve strain 5A cultured with 50 μM As(III); ▵, As(III)-preexposed strain 5A cultured with 50 μM As(III); ⋄, Sb-naïve strain 5A cultured with 50 μM Sb(III); ⧫, Sb(III)-preexposed strain 5A cultured with 50 μM Sb(III). Symbols represent the means of at least duplicate cultures, and error bars (where visible) represent the range of the two values.