Title

Which chopstick surface, either wooden, metal, or plastic, would enable the most E coli bacteria to grow?

School Name

Heathwood Hall Episcopal School

Grade Level

11th Grade

Presentation Topic

Microbiology

Presentation Type

Non-Mentored

Abstract

The purpose of this study is to determine how the type of chopstick surface effects the growth of Escherichia coli bacteria in a controlled environment. The hypothesis is that on a wooden chopstick surface, that is of rougher texture than plastic and metal, the bacteria will live longer and grow faster than on a smooth, hard surface chopstick surface. After growing the Escherichia coli bacteria cultures, the sanitized chopstick surfaces were contaminated with the bacteria and allowed to dry. The chopsticks were rinsed in nutrient broth to remove bacteria that adhered to the surface. The rinse solution was transferred to nutrient agar plates and allowed to incubate under controlled conditions. The independent variable was the type of chopstick surface (soft bamboo wood, hard painted wood, metal, and plastic), the dependent variable was the count of bacterial colonies after 48 hours and 72 hours at 37oC in an incubator, providing a direct measure of the survival and potential growth of bacteria on the different surfaces. The bacteria in the colonies were then counted using computer software. For each surface, five different samples were prepared to gain information about reproducibility. The results clearly showed that the plastic surface favored the growth of bacteria, while both wooden surfaces and the metal surface clearly showed lower bacterial counts. The inferential statistics added another level of support for the conclusion that there is in fact a significant difference between the materials used in experimentation and their ability to sustain bacterial contamination.

Location

Neville 221

Start Date

4-14-2018 11:45 AM

Presentation Format

Oral and Written

COinS
 
Apr 14th, 11:45 AM

Which chopstick surface, either wooden, metal, or plastic, would enable the most E coli bacteria to grow?

Neville 221

The purpose of this study is to determine how the type of chopstick surface effects the growth of Escherichia coli bacteria in a controlled environment. The hypothesis is that on a wooden chopstick surface, that is of rougher texture than plastic and metal, the bacteria will live longer and grow faster than on a smooth, hard surface chopstick surface. After growing the Escherichia coli bacteria cultures, the sanitized chopstick surfaces were contaminated with the bacteria and allowed to dry. The chopsticks were rinsed in nutrient broth to remove bacteria that adhered to the surface. The rinse solution was transferred to nutrient agar plates and allowed to incubate under controlled conditions. The independent variable was the type of chopstick surface (soft bamboo wood, hard painted wood, metal, and plastic), the dependent variable was the count of bacterial colonies after 48 hours and 72 hours at 37oC in an incubator, providing a direct measure of the survival and potential growth of bacteria on the different surfaces. The bacteria in the colonies were then counted using computer software. For each surface, five different samples were prepared to gain information about reproducibility. The results clearly showed that the plastic surface favored the growth of bacteria, while both wooden surfaces and the metal surface clearly showed lower bacterial counts. The inferential statistics added another level of support for the conclusion that there is in fact a significant difference between the materials used in experimentation and their ability to sustain bacterial contamination.