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Name: Jordyn B.
Status: Student
Age: 13
Location: N/A
Country: N/A
Date: September 2004

I am doing a science project at my school. I would like to do the effect of pH on bacterial growth. I have access to nutrient agar through my mom's work, but we don't know how to make the agar at different pH's. Is this possible and if so how? Would another way to do the experiment be by changing the pH of water infected with bacteria and then using the membrane filter technique to to see at which pH the bacteria survived?

Good idea..u can adjust the pH with sodium hydroxide or HCl.


That sounds like a great idea if you have a membrane filter apparatus. You may be able to inoculate bacteria into nutrient broth instead of on agar and then add different concentrations of acid/base to the nutrient broth, membrane filter the bacteria after a period of growth in the broth, and then put the filters on nutrient agar to see how many grow. You would need appropriate controls. Have a chemistry teacher help you with the amounts of acid/base you might need to get a certain pH.


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