You are working with a Gram positive bacterium that can be grown in Tryptic Soy Broth, a complex medium, or in a defined medium containing glucose, ammonium sulfate, potassium phosphate, ferric chloride, sodium phosphate and magnesium sulfate.

You suspect that the amount of iron in the defined medium would affect the growth rate. Describe an experiment you could do to test this hypothesis. Be sure to describe the growth conditions and the methods you would use to determine if iron affects the growth rate.