Figure 3.Bacillus subtilis strain 1A100 ΔlysPGS is susceptible to β-lactam antibiotics. The presence of LysPG in the membrane allows B. subtilis 1A100 (red) to resist the effects of the cell wall targeting, β-lactam antibiotics azlocillin (green), and cefsulodin (pink). Concentrations of azlocillin and cefsulodin were used at the minimum inhibitory concentration of the ΔlysPGS strain corresponding to 50 μg/mL and 2.5 μg/mL, respectively. The absence of LysPG in B. subtilis 1A100 ΔlysPGS does not result in a growth defect in the absence of antibiotic (blue), but causes decreased growth compared with the wild type strain in the presence of azlocillin (black) and cefsulodin (purple). Data represent averages of three independent experiments and the corresponding standard errors.