FIG 1.

Analysis of lldPRD transcription in response to various stimuli in vitro. The S. Typhimurium wild-type strain and a ΔlldR mutant strain were grown in mucin broth. Nitrate (NO₃⁻) and l-lactate were added as indicated at concentrations of 40 mM and 20 mM, respectively. Cultures were grown for 3 h anaerobically (no electron acceptor and nitrate conditions) or in the presence of 1% oxygen. RNA was extracted, and lldP (A), lldR (B), and lldD (C) mRNA levels were assessed by RT-qPCR. Transcription was normalized to that of the housekeeping gene gmk. All experiments were conducted with at least 3 biological replicates. To determine differences between groups, a two-tailed, unpaired Student's t test on ln-transformed data was used. Bars indicate the geometric mean ± standard error. *, P < 0.05; **, P < 0.01; ***, P < 0.001.