Science Buddies: "Ask an Expert"

When working with meat, what is the best type bacteria to use as part of an experiment?

Hi Kamaria,

Can you provide us a little more information about your project? What are your question and hypothesis? I can glean a little information from the title, but if you could let me know what exactly you're trying to test, I can advise you better.
Generally, E. coli and Salmonella are commonly used for food safety tests, but I would really need to know more about the project to advise what would work in your specific case.

Thanks,
scibuddyAK

Hello there,

I agree with the previous expert that if you could provide a little more detail about your question, hypothesis, and experimental approach, we'll be able to provide more helpful advice to you. Are you trying to figure out which methods of thawing/cooking meat are able to minimize the amount of bacteria on the meat the best? Let us know more and we'll be glad to help you brainstorm ideas!

Connie

The purpose of my project is to determine which method of thawing meat is safest and which method of cooking kills the most bacteria. I will be doing three test. The first test is to thaw meat at room temperature vs. the refrigerator. The second test is to cook two of each of the meat samples in the microwave. The meat samples I will be using are the samples that were thawed in test 1. The third test is to cook two more of each of the meat samples in a standard oven. At the end of each test I will take a bacterial count. Is there a certain type of agar I should use when making my agar plates?

Hi there,

Since you don't know what kind of bacteria that would be present on your meat, I would just use standard nutrient agar sold by Carolina Biologicals (http://www.carolina.com/prepared-biolog ... /821862.pr). They should support the growth of a variety of microbes.

You have a great foundation so far for your proposed experimental procedures. How are you planning to get bacteria from your meat to do counts though? Are you going to swab the surface of the meat and plate that on agar? Are you going to grind the meat up and plate the homogenate? One thing that's important to keep in mind is that you plate the same amount of meat for each condition to ensure that you can compare the quantities of bacteria between the two samples. You may also want to plate a sample of each of your meats after thawing at room temp vs. the fridge to see how many bacteria are present, and then plate a sample of each of your meats again after either cooking them in the microwave or in the oven to observe which combination of thawing/cooking will reduce the amount of bacteria. Again, you have to be mindful that you're plating the same amount of each sample so you can compare the numbers you get from the counts.

Let us know if you have more questions!

Connie