FIGURE 10: S. Typhimurium responds to exogenous riboflavin under DMB stress, but growth cannot be fully recovered. (A) Cells were grown in lysogeny broth with (squares) or without (circles) riboflavin (0.75 mM). Cultures with added DMB (2 mM) are shown in filled shapes. Black colored graphs represent araB9 strain (JE10079) and orange graphs represent ara9 /pPnuX+ (JE26910) strain harboring C. glutamicum riboflavin transporter gene pnuX in trans. (B) Heterologous expression of C. glutamicum riboflavin transporter gene pnuX increased its sensitivity to roseoflavin, a toxic analog of riboflavin; cultures were grown in lysogeny broth containing roseoflavin (500 μM). l-(+)-Arabinose (0.5 mM) was added to the medium to induce gene expression. Error bars represent standard deviation of three technical replicates and each experiment was completed with three biological replicates, with a representative graph shown.