Many kinds of molds produce antibiotics that can slow down the growth of bacteria. if you were looking for a new antibiotic produced by a particular mold, how might you do this properly?

Explanation:

Based on the information provided within the question it can be said that in order to properly look for the new antibiotic you must first grow the mold in a large vat, once that is done the next step would be to purify chemicals from the vat, in order to see if any of the chemicals can interfere with the growth of bacteria on the petri plate.  This will allow you to properly find if a particular mold creates a new antibiotic.

the endomembrane system i think