Figure 2

NaSA stimulates EPS synthesis in XKK12 WT (pPIP122) in an OryR-dependent manner. (A), EPS production of XKK12 WT (pPIP122) grown on PSA plates with or without 1 mM NaSA. Data are means ± SE of three plates. Asterisks indicate statistically significant differences compared to the control (T-test: n = 3; α = 0.05). (B), Effects of 1 mM NaSA and/or 3 μM DSF on EPS production of XKK12 WT (pPIP122) grown in PY broth. Data are means ± SE of three replicates. Different letters indicate statistically significant differences (Tukey: n = 3; α = 0.05). (C), Effect of 1 mM NaSA on EPS production of XKK12 WT, oryR ⁻ and oryR ⁻ complemented strain (oryR ^-+) grown in PY broth. Data are means ± SE of three independent experiments. Asterisks indicate statistically significant differences compared to the control (T-test: n = 3; α = 0.05). (D) and (E), Effect of 1 mM NaSA on expression profiles of oryR and the EPS biosynthesis gene gumG in PY-grown XKK12 WT (pPIP122). Data are means ± SE of two technical and two biological replicates. Asterisks indicate statistically significant differences compared to the control (T-test: n = 4; α = 0.05). (F), oryR gene promoter activity in XKK12 WT harboring the reporter plasmid pORYR122 (Ferluga and Venturi, 2009) grown in PY broth supplemented or not with 1 mM NaSA. Data are means ± SE of three replicates from a representative experiment. The experiment was repeated twice with similar results. Asterisks indicate statistically significant differences compared to the control (T-test: n = 3; α = 0.05).