1. Carly Werner Period 6 May 23, 2014 Discovery Project Biology
Counting Copious Colonies How does disinfectant method affect amount of bacteria still growing?
Carly Werner
Period 6
May 23, 2014
Discovery Project
Biology

2. Field Description Biology The study of living organisms.
I chose this field of study because I had little knowledge on the subject and wanted to learn more.

3. Future Job Opportunity
Microbiologist
Research assistant
A research assistant provides technological support for a scientist to carry out his studies and investigations.
Relates to field because a research assistant gathers knowledge on the field of microbiology and prepares the microbiologist for his or her own investigations.

4. Timeline
The discovery of microorganisms was made during the time period in between 1665 through Robert Hooke and Antoni van Leewenhoek were the two scientists who discovered the existence of microorganisms. This discovery changed the way of preventing and killing infectious disease.
In 1881, scientist Fanny Hesse invented agar. Agar is the substance that microorganisms sit on when in a sterile plate. This invention helped scientists get a more accurate view of the structure and movement of microorganisms.

5. Experimental Design Diagram
Title: How does disinfectant method affect amount of bacteria still growing? Hypothesis: If the disinfectant method is antibiotic soap and hot water, then a very small amount of bacteria will still be growing, because antibiotic soaps contain bacteria killing substances. Independent Variable: Disinfectant Method
Levels of the IV:
Antibiotic Soap and Hot Water
Hot Water Rinse
Salt Water Soak
Hydrogen Peroxide
Solution
Number of Trials: 2

6. Background Research
Due to the fact bacteria is grown specifically so scientists can observe the individual colonies, the growth patterns differ from the same bacteria that grows in the wild.
The pattern of bacterial growth depends on the amount of change in the bacteria’s environment.
Another factor that affects bacterial growth result from nutrient agar concentration.

7. Procedure Safety: Always wear gloves and never allow bacteria to touch your skin directly.

8. Creating Sterile Plates

9. Creating Sterile Plates

10. No Method

11. Hot Water Method

12. Hot Water and Antibacterial Soap Method

13. Salt Water Method

14. Hydrogen Peroxide Method

16. Data Table
How does disinfectant method affect amount of bacteria still growing?
Independent Variable:
Dependant Variable: Amount of Bacteria Still Growing
(Bacterial Colonies)
Disinfectant Method
Trial 1
Trial 2
Average
Hydrogen Peroxide
5.0
3.0
4.0
Hot Water
22.0
6.0
14.0
Hot Water and Antibacterial Soap
13.0
13.5
Salt Water
10.0
7.0
8.5
No Method
11.0
9.0

17. Graph Amount Of Bacteria Still Growing (Bacterial Colonies)
Disinfectant Method

18. Conclusion
How does disinfectant method affect amount of bacteria still growing?
The hydrogen peroxide soak left the least amount of bacteria still growing.
4.0 bacterial colonies in average.
Hydrogen peroxide contains bacterial killing substances.
The hot water rinse, on average, left the most bacteria growing.
14.0 bacterial colonies
The toothbrush was not able to rinse out long enough under the hot water.
There was a rip in the nutrient agar.
*restate hypothesis, CER, comparison

19. Application
-To improve the experiment, instead of soaking the toothbrush in soap and hot water, the soap should be rubbed on the toothbrush directly, then rinsed off with hot water. -This experiment relates to killing bacteria outside of a lab. For example, when you cut a huge cut, you would rub hydrogen peroxide on it to kill the harmful bacteria. -A future experiment would be: How does temperature affect bacterial growth?
Connect

20. Work Values
-Knowledge -Learning and gaining information. -Work value was met. -Location -Working somewhere that provides pleasure. -Work value was not met. -Adventure -Coming across new and exciting things.
*Elaborate