Fig. 1: Induction of flagella production and motility in E. albertii by low salt and low nutrient concentrations.
From: Hypoosmotic stress induces flagellar biosynthesis and swimming motility in Escherichia albertii
a Cells of E. albertii strains were cultured in semi-solid 1/10TSB at 20 °C for 3 days. Four strains (HIPH08472, HIPH12313, HIPH14005, and HIPH16576) showed “umbrella-like” growth at the upper part of the stab lines, indicating that they are motile and aerobic condition enhances their motility. Two strains (HIPH12338 and HIPH14564) were non-motile and grew only along the stab lines. b–h Scanning electron microscopy images of E. albertii strains cultured in TSB (b) or 1/10TSB (c–h) at 20 °C. No flagella were observed in HIPH08472 cells cultured in TSB (b), while several flagella were clearly observed on both pole and lateral when cells were cultured in 1/10TSB (e). Flagella were also observed in other motile strains such as HIPH12313 (f), HIPH14005 (g), and HIPH16576 (h), but not in the non-motile strains HIPH12338 (c) and HIPH14564 (d). Scale bar: 1 μm. i Induction of the flagellar genes flhD and fliD by low-salt and low-nutrient levels. The amount of mRNA was measured by qRT-PCR. Data are shown as means ± s.d. (n = 3 biologically independent samples). **P < 0.01, ***P < 0.001, *****P < 0.00001.
