You can add PEG6000 (5-40%) in your media to create drought conditions. Usually due to high conc. of PEG will not allow agar medium to solidify so you can supplement it in broth and use it for screening selected microbes

Use of Copper sulphate or Sodium Chloride in Nutrient Medium may help grow drought resistant bacteria

Humera--I can make a suggestion. The bacteria that are most tolerant to lack of moisture and nutrients in soils--may be the endospore formers like Bacillus spp. If you want these bacteria you could pasturize the drought subjected rhizosphere soil by heating it at 50C for 2 hours--then plate the soil onto 10% Tryptic Soy Agar--or a richer medium that contains yeast extract. The pasturization process will kill the bacteria that cannot form endospores. If you still get non-endospore formers after 2 hours of pasturization increase the time. We use this method to isolate endospore-forming endophytes from plants, many of which are also drought resistant. Good luck. Jim White

Thanks a lot dear James White, I am going to try it, it seems to be helpful.

Hello Humera,

There is a positive correlation between tolerance to desiccation and resistance to ionizing radiation; therefore, one strategy is to irradiate your sample before isolating drought-resistant strains. Specific media would help you isolating specific (desiccation tolerant) taxa. 

In case you do not have an accessible irradiation facility, you might use in your growth medium molecules that cause similar damage to DNA (mitomycin c (MMC), etc.).

All the best,

Haïtham SGHAIER

Dear colleges,

how to convert PEG6000 concentration in osmotic pressure?

I added 5, 25 and 50% v/v PEG 6000 in nutrient broth and I have difficulties converting that in MPa.