Fig. 5.

Effect of glutamine on the PTS regulatory cascade of Rlv3841. (A) Effect of nitrogen availability on AIB transport. Membrane transport of wild-type cells grown on UMS with 10 mM glucose as carbon source and 10 mM NH₄Cl, glutamine (N-rich conditions) or glutamate (N-limiting conditions). (B) Effect of glutamine addition on AIB transport. Wild-type cells grown on UMS with 10 mM glucose as carbon source and 10 mM NH₄Cl (N-rich conditions) or 10 mM glutamate (N-limiting conditions). Transport rates measured at 1 min and 10 min after glutamine addition. All transport rates are expressed in nmol min⁻¹ mg protein⁻¹. (C) Effect of glutamine addition on O₂ consumption of cells grown under different nitrogen conditions. Wild-type cells grown on UMS with 20 mM succinate as carbon source and 10 mM NH₄Cl (N-rich conditions) or 1 mM NH₄Cl (N-limiting conditions). Values show the rates of O₂ consumption expressed in μmol L⁻¹ min⁻¹ OD_600nm^-1. (D) Effect of glutamine addition on O₂ concentration over time. Graphical representation of O₂ concentration (ppb) over time (min) for cells with no glutamine added (Top line, filled dots) compared to cells after the addition of glutamine (100 μM) indicated by a blue arrow (Bottom line, empty dots). Conditions are as above. Data are averages (±SEM, at least three independent cultures). Two-way ANOVA with Sidak’s multiple comparisons test (*) P < 0.05, (**) P < 0.01, (***) P < 0.001 (****), P < 0.0001 and n.s. not significant.