Surface Microbiology and Antiseptic Science Fair Projects

Bio-control Agents in Your Home

While the term "bio-control agent" seems like the name of a weapon, it is basically just something that is used to control the growth or life cycle of an organism. There are many bio-control agents that we use each day. Some of these agents are used to accelerate growth of organisms while others are used to slow down growth or to kill organisms.

PURPOSE

The purpose of this experiment was to determine which mouthwash was most effective in killing alpha streptococcus.

I became interested in this idea while brushing my teeth and wondered if the bacteria in my mouth were being killed.

The information gained from this experiment would help consumers and dentists find the best solution for killing and preventing bacteria in the mouth.

HYPOTHESIS

My hypothesis was that Listerene Antiseptic Mouthwash would kill the most alpha streptococcus.

I based my hypothesis on what Marie Clark, Microbiologist at Memorial Hospital, said: "Listerene as an antiseptic should be the best at inhibiting alpha streptococcus." I also based it on the fact that it was approved by the American Dental Association (ADA).

EXPERIMENT DESIGN

The constants in this study were:

• The amount of mouthwash used
• Number of mouthwash types per plate
• Number of control groups per plate
• The type of plates used
• Same blood and broth mixture in plates
• The type of bacteria used
• The approximate number of organisms per plate
• Same death zone measurement method and tool

The manipulated variable was the type of mouthwash used.

The responding variable was the size of the death zone around the area where the mouthwash was placed.

To measure the responding variable a caliper was used to measure the diameter of the circle of death zone in millimeters.

MATERIALS

Microbiology antiseptic science fair projects continue at clean biology science fair projects.

Bacteria is a fascinating subject to study.