Repression of nanAB locus by glucose. (A) Growth curves of FP65 in medium supplemented with glucose (closed circles), ManNAc (open triangles), and glucose plus ManNAc (open squares). (B) Growth curves of PF65 in medium supplemented with glucose (open circles), NeuNAc (open triangles), and glucose plus NeuNAc (open squares). The arrows indicated sampling. (C) Gene expression of SPG1598, SPG1592, and SPG1591 in medium supplemented with amino sugars are compared to growth in glucose. Variation of gene expression is shown for genes of bacteria grown in ManNAc (open bars), glucose plus ManNAc (open striped bars), NeuNAc (grey bars), and glucose plus NeuNAc (grey striped bars). Results are represented as fold changes ± SD of gene expression from 3 to 4 independent experiments. Statistical analysis was carried out using Tukey’s Multiple Comparison Test (ns non significant; *, p < 0.05; **, p < 0.01). Generation time on glucose containing media is 38–45 min, 90 min on NeuNAc and 140 min on ManNAc.