How do certain substances inhibit or promote bacterial growth?
There are many kinds of bacteria, but a great many of the bacteria that you encounter daily share similar growth requirements. In this experiment you will investigate substances that affect the growth of common household bacteria. You will collect a sample of bacteria from one of numerous possible sources. You can use your imagination on where to collect the bacteria. Because bacteria need moisture to live, possible sources include the base of a faucet, on someone’s hands, inside someone’s cheek, or on a bathroom doorknob. You will then streak the bacteria on a growth substance. Bacteria grow well on a substance called agar. Nutrient agar is a jellylike substance that contains food for the bacteria. You can order prepared nutrient…
