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Name: Agatha M.
Status: Educator
Age: 30s
Location: N/A
Country: N/A
Date: 2002

I would like to test bottled and tap water for any bacteria and I'm wondering what kind of bacteria will I find growing in the petri dishes? I am doing this experiment with the student that I tutor. Thanks for your help.

I hope you do not find ANY bacteria. As long as the bottle has not been opened, it should be fairly bacteria-free. If you do find any, it should be fairly innocuous species.


Let your student brows the water safety display of the Virtual Museum of Bacteria

(direct link:

For your info is an annotated list of links on bacterial contamination of water at

Trudy Wassenaar
Curator of the Virtual Museum of Bacteria

If it is chlorinated water not much will grow and of course you would need a control petri dish group of sterile water. Millipore and a few other companies sell a cheap water culture kit. You can also get simple tests done free at your extension agency...a trip there is always interesting.

Peter Faletra Ph.D.
Assistant Director
Science Education
Office of Science
Department of Energy

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