FIG. 1.

Analysis of the adaptive response to SNP in B. subtilis. Cultures were grown aerobically and treated with a sublethal concentration (0.5 mM) of SNP or left untreated (for details, see Materials and Methods). The cultures were then challenged with 10 mM SNP for 30 min, and dilutions were plated on TBAB medium. Viable counts were performed, and survival rates were calculated as the CFU after treatment with a toxic dose of SNP divided by the CFU in the same culture treated with water. Strains 1A1 (wild type [wt]), LUW260 (Δhmp), LUW264 (ΔresDE), LUW340 (ΔnsrR), LUW260/pDG148, LUW260/pDG148-hmp, and LUW229 (ΔsigB) were used. The results shown are the means from at least three independent experiments. Error bars indicate the standard deviation.