Fig 7.

Hyperosmotic exposure cross-induces protective and detrimental effects on oxidative and heat shock stress responses, respectively, and the capsular polysaccharide protects against salt stress. (A and B) Bacteria were incubated in 1.0% NaCl for 2 h and then exposed to 5 mM H₂O₂ over 40 min (A) or 45°C conditions over 120 min (B). Cross-protection against oxidative stress but decreased tolerance to thermal stress occurred following hyperosmotic shock. Error bars are from three biological replicates. (C) Serial 10-fold dilutions of OD-standardized wild-type and ΔkpsM bacteria were spotted on MH agar with or without 0.8% NaCl. The ΔkpsM mutant exhibited increased sensitivity to hyperosmotic conditions. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001.