Stress challenge experiments.

Two M. smegmatis cultures were inoculated into carbon-limited medium to an initial OD600 of approximately 0.001. One culture was grown to mid-exponential phase (OD600, approximately 0.5), and the other was grown to approximately 8 h into stationary phase. A stress condition was then applied to both cultures, and survival was monitored over a period of 3 to 9 h by viable plate counting. Oxidative stress was applied by adding H2O2 to a final concentration of 18 or 36 mM. Osmotic stress was applied by the addition of NaCl to a final concentration of 5 M. NaCl (2.92 g) was quickly dissolved in 10 ml of culture by vortexing for 30 s. Acid stress was applied by adding 1 M HCl to lower the pH to 2. The pHs of the cultures were checked at the start and end of the experiment with pH indicator strips.

Hi Varun

Since you re using Midelbrook 7H9 , that is rich liquid medium. The stationary phase can be reached at 0.7 to 0.8.  Be carefull to make a vial of 7H9  as blank (yellowish)