Science Buddies: "Ask an Expert"

I am doing A SCIENCE FAIR PROJECT where I tested for bacteria on drinking fountians. How much is to much bacteria?

Thank you

Hi kevala,

I want to help you answer your question, but I need a little more information. What is your hypothesis and how exactly are you testing it? How are you quantifying the bacteria and what is your control?

It sounds exciting!

Cheers,
Emily

I am using 3 different kinds of agars. The first one is Nutrient Agar this will grow almost any kind of bacteria and I am using it for a general count. The next agar I am using is MaConkey Agar w/MUG this allows for gram negtive bacteria to grow. I also used Mannitol Salt Agar, this allows gram positive bacteria to grow.

I divided each plate into 4 categories one had bacteria from the spout, the other from the bowl, the other from the handle and the fourth I used as a control. No bacterial colonies grew on the control space.

I found all kinds of bacteria, including e.coli and members of the staphylcoccus family.

Hi Kevala,

That is a cool project and it is good that your no bacteria control is negative. I do not know if you can ever have too much bacteria, but you can always talk about relative amounts of different kinds of bacteria from different parts of the drinking fountain. It might be interesting to clean that drinking fountain and try the experiment again so that you have a comparison between the bacteria found on a well used fountain and a clean one...

Cheers,
Emily

Thank you that is a good idea!