1. One of the oldest food preservatives is salt.  How does salt control microbial growth and reduce spoilage?

2.Adding salt to preserve foods is least likely to be effective against bacteria from which of the following?

Bacteria found in your ‘gut’   Bacteria found on your skin   Bacteria found in your mouth

3. One would think the potent poison potassium cyanide (KCN) would be toxic to bacteria also.  Instead, potassium cyanide can actually serve as a source of nutrition to support the growth of certain bacteria.  Provide an explanation for its toxicity to humans and its lack of toxicity/ability to support the growth of some bacteria.

4. List below two culture media employing an inhibitor to prevent the growth of unwanted microbes.  Explain how the inhibitors accomplish their task and indicate which group of microbes is inhibited.

5.  List below two media that are selective because they contain a sole source of carbon that is not used by all bacteria.