1. Effects of Eco-friendly Cleaners on Bacterial Survivorship
Max Kaufmann
Central Catholic High School
9th grade

2. Problem
Do environmental friendly cleaning products have a negative impact on bacterial survivorship and do they work as well as cleaning products using traditional chemistry?

3. Mrs. Meyer's Clean Day Multi-Surface Everyday Cleaner
Ingredients
- 98% derived from plants
-All ingredients are biodegradable
-Sodium Methyl 2-Sulfolaurate is the main cleaning agent
-All ingredients are safe for pets and children

4. GS Neutral Disinfectant Cleaner (NDC)
-Industrial use cleaning product
-Ingredients are “Hazards to Humans”
-Ingredients :
Alkyl dimethyl benzyl ammonium chloride
Octyl decyl dimethyl ammonium chloride
Dioctyl dimethyl ammonium chloride
Didecyl dimethyl ammonium chloride

5. Escherichia coli (E. coli)
-The Strain that was used is E.coli C
-Lives in the intestinal tract of many mammals
- Most forms are harmless, but some can become pathogens
- Serves as a common prokaryotic cell model
- Widely used in many experiments

6. Purpose
The purpose of this experiment is to test if an eco-friendly cleaner, Mrs. Meyer's Clean Day Multi-Surface Everyday Cleaner, affects bacterial survivorship, and how it compares to a normal cleaning product.

7. Hypothesis Alternative hypothesis:
Each of the cleaners will reduce E.coli survivorship. The NDC will reduce survivorship more than the Mrs.Meyers product.
Null hypothesis
Neither of the cleaners will reduce survivorship and will not vary significantly in effect.

8. Materials -E. Coli C -Incubator -Vortex
-GS Neutral Disinfectant Cleaner
-Mrs. Meyers Clean Day Multi-Surface Everyday Cleaner
-Tubes
-Various sized pipettes
-56 LB agar plates (1% Tryptone,0 .5% Yeast Extract, 1% NaCl)
-Sterile Dilution Fluid (SDF) (per 1 liter) (100mM KH2PO4 , 100mM K2HPO4 , 10mM MgSO4 , 1mM NaCl)
-Sterile pipette tips
- Cell spreaders
-Ethanol alcohol
-Open flame

9. Cleaning product exposures
Agar infusion:
Adding variable to plate before placing the microbe
Liquid pulse:
Exposure created by adding variable and microbe in SDF then spreading onto plates

10. Procedures Agar Infusion
The ingredients were mixed to create the exposure of the variable
For a low exposure NDC and 10% Meyers, 20 ul of variable and 180 ul of SDF was pipetted onto 6 plates, then spread evenly with a sterile cell spreader
For a high exposure NDC and Meyers, 200 ul of variable was pipetted onto 6 plates, then spread evenly with a sterile cell spreader
After two hours, 100 ul of E.coli was added from control tube then was spread onto all of the plates
Plates were incubated for 2 days at 37 degrees celsius
Number of bacterial colonies were counted visually

11. Concentration Table of Agar Infused Plates
Meyers 100%
Meyers 10%
NDC 100%
NDC 10%
Variable
200 ul
20 ul
SDF
0 ul
180 ul
Total

12. Procedures Liquid Pulse
The ingredients were mixed to create the exposure of the variable using the concentration table and placed in a tube
All solutions were vortexed
0.1 ml of all solutions was pipetted onto six plates for each group
Plates were then spread evenly with a sterile cell spreader
Plates were then incubated for two days at 37 degrees celsius
Number of bacterial colonies were counted visually

13. Concentration table of Liquid Pulse
100% stock of cleaners created (variable)
Meyers 10%
Meyers 1%
NDC 10%
NDC 1%
Control
E. Coli
0.1 ml
SDF
8.9 ml
9.8 ml
9.9 ml
Variable
1 ml
0.1ml
0 ml
Total
10 ml
10ml

15. ANOVA of Liquid Pulse
SUMMARY Groups Count Sum Average Variance Control Meyers 10% Meyers 1% NDC 10%
NDC 1% ANOVA Source of Variation SS df MS F P-value F crit Between Groups Within Groups Total

16. Dunnett's test of Liquid Pulse
T-crit = 3.26
Groups
T-Value
Interpretation
Meyers 10%
56.5
Significant
Meyers 1%
9.4
NDC 10%
67.3
NDC 1%

18. ANOVA of Infused Plates
SUMMARY Groups Count Sum Average Variance Control Meyers 100% Meyers 10% NDC 100% NDC 10% ANOVA Source of Variation SS df MS F P-value F crit Between Groups Within Groups Total

19. Dunnett's Test of Agar Infused Plates against control
T crit = 3.26
Groups
T-value
Interpretation
Meyers 100%
42.3
Significant
Meyers 10%
19.8
NDC 100%
59.3
NDC 10%
8.5

20. Dunnett's test of results between the two variables
T Crit = 3.26
Infused Plates
T-value
Interpretation
100% var. concentration
19.3
Significant
10% var. concentration
12.8
Liquid Pulse Plates
T-value
Interpretation
10% var. concentration 51
Significant
1% var. concentration
9.5

21. Conclusion
The null and alternative hypotheses are rejected, Both cleaners significantly reduced bacterial survivorship, but the NDC had only killed off more bacterial colonies for ¾ of the concentrations compared to the Mrs. Meyers cleaner.
-Meyer’s LD50 for the agar infused is approximately 100 ul and LD50 for the liquid is 6%
-The Neutral Disinfectant Cleaner LD50 could not be determined due to at least one group per liquid/infused had eliminated all of the bacteria.

22. Limitations
-During infusion, solution might not have completely absorbed into agar before microbe was plated
-Incubation time period
-Only the effect on survivorship was tested
-Bacteria colonies grew to close together to on a few of the plates to get an accurate cell count
-Only high and low concentrations used

23. Further experiments -More trials -Different bacteria
-More concentrations and doses
-Other effects on bacteria
-Different ways of testing

24. References - - - -