Increase in catalase activity and hydrogen peroxide resistance of Xac cells in a plant-like medium.

a. Xac cells were grown in the indicated media to early exponential or stationary phase and then harvested. Catalase activities in soluble cell extracts were measured as described in Materials and Methods.
b. Early exponential and stationary phase cultures were exposed to 1 mM and 30 mM H2O2 respectively, for 15 min. The percentage of survival is defined as the number of CFU after treatment divided by the number of CFU prior to treatment ×100.
Data represent mean ± standard deviation of three independent experiments.