FIG 7.

NtrC affects growth with different nitrogen sources and modulates glnA and vpsL expression in V. cholerae. (A) Growth curves of the wild-type and ΔntrC strains grown in defined M9 medium supplemented with 0.1% NH₄Cl, 100 mM l-arginine, or 100 mM l-glutamine as the only nitrogen source. The graph represents the means and standard deviations of data for two technical replicates from two biological replicates. (B and C) Expression of PglnA-luxCADBE (B) and PvpsL-luxCADBE (C) in the WT and ΔntrC strains grown for 4 h in the presence of 0.1% NH₄Cl, 100 mM l-arginine, or 100 mM l-glutamine as the sole nitrogen source. The graphs represent the averages and standard deviations of RLU obtained from four technical replicates from two independent biological samples. RLU are reported in luminescence counts per minute per milliliter per OD₆₀₀. Pairwise analysis was performed by using a two-tailed unpaired t test with Welch's correction. **, P < 0.01; ****, P < 0.0001.