Science Buddies: "Ask an Expert"

Hi,
I'm a freshman in high school, and i'm doing a science research project.
My topic is
"Where does the most bacteria live?"
I'm very interested in microbiology, so I'm doing an experiment involving nutrient agar plates.
I was going to use nutrient agar plates to collect and grow bacteria and count the number of them.
I have several questions,

1. How can I collect bacteria? (Can I expose the plates to the air of places? Will bacteria stick to it?)
2. How can I incubate bacteria?
3. Is there a specific way to grow bacteria on a nutrient agar plate?

hsj32,

Welcome to the Ask an Expert Forums! I am so glad that you are doing a science fair project and hope that we can be of help as you work on it. To get started, I would suggest reading the following pages:

https://www.sciencebuddies.org/science- ... 0&sk=t&sd=

https://www.sciencebuddies.org/science- ... Agar.shtml

https://www.sciencebuddies.org/science- ... tion.shtml

https://www.sciencebuddies.org/science- ... ques.shtml

After reading through these pages carefully *I would take notes!*, post back with questions that you have or things you don't understand. Then we will work together to help you understand those things!

Good luck!

Thanks for the links!
but I have one more question.

Can I collect bacteria by exposing the nutrient agar plates in the air?
Because I cannot really swab bacteria...

Hi,

Yes, exposing nutrient agar plates to the air is definitely a viable way to collect bacteria. If there are any bacteria in the air, which there always are under any normal circumstances, some of them will land in the plate. You will then be able to culture them. This sometimes won't yield as many bacteria as swabbing a specific object, and can only be used to compare general locations rather than specific objects, but it sounds like it should suit your purposes very well.

Good luck, have fun, and feel free to ask if you have any more questions.
- Emily