The Scope on Licorice Revolution Annie Lee Burnaby North Secondary Floor Location : J 30 L

This project is a biological project. The investigative question is: Can licorice root extract inhibit the growth of Streptococcus Mutans as well as mouthwash?

This biological project involves testing the effects of mouthwash and licorice root extract on oral bacteria, including a species of Streptococcus Mutans bacteria that causes tooth decays cavities in humans. What if this experiment proves that licorice root can fight and inhibit the growth of oral bacteria? Then, licorice root extract may be put into oral products such as toothpaste and mouthwash.

The materials used in this project were: An incubator, one bottle of licorice root extract, five brands of mouthwash, a bottle of spring water, 3 x 6 Pack Frozen Petri Dish with Agar, 6 cotton swabs, measuring beakers, eye dropper, tape, microscope, ruler, camera, green permanent marker, and 6 small test tubes. The basic concept used in this experiment was to first grow the bacteria in agar-filled petri dishes overnight using the incubator with a temperature of 30-35 degrees.

The next day, take the petri dishes out of the incubator. Find a random spot on the petri dish and mark the spot. Photograph under a microscope what if under that spot. After the photographing is done, each brand of mouthwash, licorice extract, and water will be poured on the petri dishes. The dish with the spring water will serve as the control for the experiment. After this is done, the liquids will stay in the dishes for about 45 seconds, which is about how long people usually keep mouthwash in their mouths. The eyedropper will then be used to suck back out the liquid from the dishes.

The petri dishes will be placed back into the incubator overnight. The next day, the petri dishes will be taken back out, and the same place that was marked will be observed under the microscope. The results will then be compared and graphed.

Like most experiments, there are some sources of error. One may be the fact that some colonies shifted places while the mouthwash was poured onto the dish, which affected results since only half of what was originally in view could be seen. Another error is that the only colonies affected results were only those that were able to be seen with the naked human eye through a microscope through the power of 40x. The last source of error is that some bacteria in the different dishes grew more rapidly than the others. This should really not have happened, but yet again, it was uncontrollable. These errors were tried to be avoided with control variables during the experiment procedures.

In conclusion to the experiment, mouthwash C worked best. This was figured through the counting of bacteria and through what was seen in the microscope. The answer to the main question to this whole experiment is that licorice root CAN inhibit growth of oral bacteria, but some mouthwash may have worked better than it.