Confused on a medium described in an article

[Previous Community Member]

Heyo!

I'm a high-school student in my senior year. For a scientific research project, my group will be attempting to isolate penicillin from bread mold. On a website explaining the process (linked below), it says to create a mixture of chemicals for a medium. What exactly is it making? Is it just some sort of agar or growth medium?

Thanks for your help!

Dissolve the following ingredients, in the order listed, into 500ml of cold tap water: 44.0 grams Lactose Monohydrate, 25.0 grams cornstarch, 3.0 grams sodium nitrate, 0.25 grams magnesium sulfate, 0.50 grams potassium phosphate mono, 2.75 grams glucose monohydrate, 0.044 grams zinc sulfate, 0.044 grams manganese sulfate. Then add enough cold tap water to make one liter. Use hydrochloric acid to adjust the pH to between 5.0 and 5.5.

http://www.howtodothings.com/health-fitness/how-to-make-penicillin

[scooke · Accepted solution]

Dear Drew,

Yes. In general, a "medium" simply means the surroundings.  It may be a solution, an atmosphere (gas) or even a solid.  It is often used as "short-hand" for an agar growth medium in biology, but that is just a specific application of the term to that science.  In this case you will not be using agar as a substrate, but the particular combination of nutrients specified in the procedure.

Best regards,

Steven Cooke

[Previous Community Member]

That's what I was thinking. Is there a particular name for the specific solution/medium that they describe? Or is it some proprietary formula? (i.e. can I buy this pre-mixed?)

[scooke]

Dear Drew,

No.  There are a whole variety of compounds and compositions that could be used.  Commercially it is now a completely different process. https://www.news-medical.net/health/Penicillin-Production.aspx   The test you are doing is a small-scale demonstration that will also likely have fairly small yields of the product.    What you are doing is trying to see IF penicillin was produced with your bread mold by taking a sample of the mold and trying to increase the production/growth of penicillin specifically to observable quantities.

Best regards,

Steven Cooke