Science Buddies: "Ask an Expert"

My group is trying to grow bacteria in agar to test for bad breath. Bad breath is caused by the sulfur compounds, the product of the breakdown of foods by the bacteria in our mouth. Garlic itself has the sulfur compounds, so to save time, my group wanted to put garlic (juice or shreds or something, not the entire garlic piece) onto agar plates. However, I have no idea if the plates with "grow" garlic. Would the garlic "grow" in the agar plates like bacteria from our mouth would?
Thank you for your help in advance.

Hi,

That sounds like an interesting project!

Actually, garlic does cause bad breathe, but it also has anti-microbial properties, so it might not be the best choise as a source of bacteria for your project. You will find more information here:

http://en.wikipedia.org/wiki/Garlic

http://www.ncbi.nlm.nih.gov/pubmed/10594976

http://www.aafp.org/afp/2005/0701/p103.html


Depending on the concentration of garlic (liquid) used on the plates, I would not expect much bacterial growth.

Just to add to that, garlic is a part of a plant (I suggest you do some background reading on this!) and thus will not grow in an agar plate like bacteria would.

Yes, I know that. My lab partners didn't just put garlic into the agar plates. We mixed the garlic with saliva.

Hi eclara,
To help you fine-tune your research project, what is the hypothesis that you are testing? That will enable you (and us) to map out a direction for your project.

Looking forward to assist you,
CKline

It's fine now, I've already finished the experiment and now I'm onto the research.

But we were testing for effect of toothpaste, mouthwash, and breath strips. The control was an agar plate swabbed with garlic; other plates were swabbed with garlic and then "treatment" was applied. Either paper squares that was dipped in toothpaste, mouthwash, or squares of breath strips. The independent variable was the product applied and dependent variable was the number of bacteria colonies that grew.