Using Yeast as a Model Organism

[scienceanddogsareawesome]

Hello!!
I am in the process of formulating my research plan for my science fair project! I was reading and finding out that baking yeast is a simple yet effective model organism for research in the biomedical field. (my project is in the biomedical field) I was wondering how to expose yeast to pathogens and test a natural resource plant extract, to see the effects of the extract on the disease tumors. I was thinking about how I will measure the effect.


Thank you so much!!!!!

[SciB]

Hi,

Baker's yeast, known by its scientific name as Saccharomyces cerevisiae can be used in medical research but only in limited ways. It is a single-celled fungus and its metabolism is very different from that of a human. You said you were thinking of using the yeast to test plant extracts against pathogens, but human pathogens do not infect yeast.

I would suggest that you use the model human pathogen, Escherichia coli to test your extracts. Scibuddies has a lot of information on using the harmless K12 strain of E. coli in science projects:

https://www.sciencebuddies.org/science- ... egulations
https://www.sciencebuddies.org/science- ... sms-safety
https://www.sciencebuddies.org/science- ... i-bacteria

Let us know more specifically what you want to test and we can better help you devise a workable way to do it. Also, check with your teacher about your school's regulations for working with microbes. If you wanted to do a project at home you will be very limited in what you can do. Most work with microorganisms has to be done in a school lab.

Hope this helps!

Sybee

[scienceanddogsareawesome]

Hi Sybee!
Firstly, thank you so much for replying! I was wondering if carcinogens will have an effect on yeast since carcinogens are chemicals, while pathogens are microorganisms that cause disease. My teacher has informed my class that we'll have to contact university labs, if we'll be doing projects that require it. Also what is the biosafety lab level (BSL) when handling carcinogens?

Thank you so much for your support!!
Sincerely,
A.D.S

[SciB]

Hi ADS,

Glad you found my post helpful. Hope we can get you on the right track to a great project!

First I think you need to define a hypothesis so you can be sure yeast is the right experimental model for the question you want to test. I use yeast in the lab but only as a way to produce certain proteins--kind of like a mini-factory.

A fungus like yeast is not a good model for cancer. Mice and human cell cultures are what we use to test carcinogens and anti-cancer drugs. If you could find a university cancer research lab that would take you on as a student, you could learn these techniques. It is an exciting field but requires a lot of knowledge and skills.

If you wanted to change your emphasis from cancer to fungal diseases, you could use bread yeast as a stand-in for a pathogenic human fungus (https://www.sciencebuddies.org/science- ... -medicines). This Scibuddies project compares the antifungal activity of several over-the-counter medicines. Since you said you were interested in certain plant extracts, you could test them by looking at their effect on growth and carbon dioxide production of baker's yeast and compare the results to a known antifungal medication.

Let us know what you want to do and we'll help you develop your project and do the experiments.

Good luck!

Sybee

[scienceanddogsareawesome]

Hi Sybee!
Thank you for your continuous guidance on my project! I was looking at different model organisms that I can possibly use in my project, and came across the zebra fish, fruit fly, and planaria. I was wondering if those organisms will be able to possibly develop tumors when exposed to carcinogens. Also not to be rude, but I would like to understand how yeast would not be a good model for anti-cancer drug research. Sorry I'm just really interested in the sciences behind certain things. In addition, if I were to use human cell cultures, where would I be able to get a hold of them? My goal in finding the best model organism is something that is effective and affordable.

Thank you so much for your assistance!
Sincerely,
A.D.S

[scienceanddogsareawesome]

Also I've read that zebrafish is considered a vertebrae. Am I going to be allowed to use zebrafish even if it is a vertebrae, due to some regulations?
Thanks,
A.D.S

[SciB]

The reason you cannot test a drug on yeast for killing cancer is that yeast are NOT cancer cells. A chemical or extract or drug might kill a yeast cell, but what would that prove? Just that you can kill yeast. That has nothing to do with treating a tumor in a human.

I don't know your institutions regulations on the use of zebrafish, but experiments on vertebrates require that your project be submitted to an institutional animal use and care committee for approval and that requires that you work in a facility that has such a committee and an appropriate lab. Apparently zebrafish embryos are not considered vertebrates until 7 days after fertilization so they could be used (https://student.societyforscience.org/v ... te-animals) but i don't know how you would test them for cancer.

Anticancer drugs and treatments are often tested on human tumor cell lines such as Hela and MCF-7 that are grown in culture in sterile flasks or Petri dishes. In order to do this you need to work in a BSL-2 facility under supervision. Human cancer cell lines are available to university researchers from the American Type Culture Collection (https://www.atcc.org/) but you would need to have access to a research lab and someone to train and supervise you.

Let us know what sort of lab you have access to and we can help you develop a hypothesis and the experiments to test it.

Sybee

[scienceanddogsareawesome]

Hi Sybee!
Your guidance has been very informative and useful, THANK YOU!! You have answered all my questions so far. I'll update you guys if any questions arise.
Thanks,
A.D.S