1. Water Source Influence of Microbial Survivorship
By Zachary Poppish
Grade 9
Central Catholic High School Pittsburgh

2. Rationale:
Water sources can vary greatly in their quality and properties.
Various types of microbes exist in natural water sources.
Do river water and creek water vary significantly in their ability to support prokaryotic and eukaryotic microbial life?

3. Common Creek and River Pollutants
Detergents
Fertilizers
Animal waste
Automotive products
Pesticides
Can runoff products aid or hinder microbial growth?

4. Allegheny River
The sample of the River was taken along the side of a railroad track.
Many pollutants in the Allegheny River from:
Tires, garbage, styrofoam, plastic, lumber and many other pollutants

5. Deer Creek
The area of Deer Creek where my sample was taken is near a small industrial park
This includes:
A metal shop that carries petroleum
A trucking distribution center.
A PennDot station with road salt
A Brick yard and Lumber Mill

6. Microbes Tested
Escherichia coli (E.coli)
Saccharomyces cerevisiae (Yeast)

7. Escherichia coli (E.Coli)
Gram-negative microflora
Found in the intestines of warm-blooded animals as well as excrement
Most varieties are harmless, though some can cause illnesses.

8. Saccharomyces cerevisiae (Yeast)
Single celled fungi
Most commonly studied organism- similar biochemistry and genes as other Eukaryotes
Gram-Positive microflora
Most commonly called yeast or baker's yeast

9. Materials used Sterile pipette tips Micropipettes Vortex Incubator
72 YEPD agar plates(1% yeast extract, 2% peptide, and 2% glucose)
Sterile pipette tips
Micropipettes
Vortex
Incubator
Spreading turntable
Spreader bar
Escherichia coli (e.coli)
Saccharomyces cerevisiae (yeast)
Sample water from Deer Creek
Sample water from the Allegheny River
Sample of SDF (100mM KH2PO4, 100mM K2HPO4, 10mM MgSO4, and 1mM NaCl)

10. Procedure
Collected samples from local creek and river in a sterile container
Sterilized the 2 water samples using 0.2 micron syringe filter
The waters were transferred to sterile 15 mL conical tubes
The yeast and E. coli were diluted from their stocks to a tube with a concentration of 10^5 cells per mL
100 microliter samples of the microbes were transferred into the water samples
The tubes were incubated at room temperature for 5 min and 1 hr
After 5 and 60 minutes 100 microliters of the mixtures were transferred to YEPD agar plates.
Plates were incubated (yeast= 37C for 48hr and E. coli 37C for 24hr)
The resulting colonies were counted

11. Variables Independent: Exposure Time/Water sample/Microbe used
Dependent: Amount of colonies
Control: SDF

12. Hypothesis
Alternative: The natural water bodies will reduce the microbial survivorship.
Null: The waters samples will not significantly hinder the microbes survivorship.

13. E. coli average colonies
P-value:
5 min:
60 min:

14. Dunnett’s Test-E. coli F-Crit:3.885 Creek River 5 min
Unable to dunnett’s test because data was not significant
1 hr
Significant
insignificant

15. Yeast Average Colonies
P-value:
5 min:
60 min:
P-value:
5 min:
60 min:

16. Dunnett’s Test-Yeast F-crit:3.885 Creek River 5 min 9.937-significant
1 hr
Unable to dunnett’s test because data was not significant

17. Percent Survivorship

18. Conclusion
The alternative Hypothesis was supported for 2 of the cases. The E. Coli survivorship was reduced after 1 hour in the creek. The creek appeared to enhance yeast growth after 5 minutes.
The null was accepted for all other waters/times.

19. Reason Different pH values? Different minerals and other ions?
Different types of pollutants?

20. Limitations Tested only one river and one creek
Only 2 time periods tested
Only survivorship and no other health parameters
Unknown composition of waters
Water was taken from river and creek during winter months

21. Improvements
Test multiple creeks and rivers to test for pollutants/different areas (RESIDENTIAL, AGRICULTURAL AND URBAN)
Do a chemical analysis of the waters
Test during different times of the year/temperatures
Test lakes and ponds for pollutants

22. Works cited https://about-ecoli.com/

23. Overall Results:I E-coli Sterilized Water 435 421 Creek Water 326 239
5 MINUTES HOUR
E-coli
Sterilized Water
Creek Water
River Water
Yeast
Sterilized Water
Creek Water
River Water
E-coli higher survivorship in 5 min versus 1 hour
Reason: Less exposure to chemicals in water

24. E-Coli: SDF
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #1 with 460 colonies
1 HR: Test #6 with 464 colonies
On Average: E-coli survivorship is higher after 5 minutes

25. E. COLI SDF (Sterilized Water)

26. Yeast: SDF
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #1 with 87 colonies
1 HR: Test #6 with 52 colonies
On Average: E-coli survivorship is higher after 5 minutes

27. YEAST SDF (Sterilized Water)

28. E-Coli: Creek Water P-Value: 0.293216
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #3 with 540 colonies
1 HR: Test #1 with 400 colonies
On Average: E-coli survivorship is higher after 5 minutes

29. E. COLI CREEK WATER

30. Yeast: Creek Water P-Value: 0.002736
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #3 with 424 colonies
1 HR: Test #2 with 60 colonies
On Average: E-coli survivorship is higher after 5 minutes

31. YEAST CREEK WATER

32. E-Coli: River Water P-Value: 0.586029
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #2 with 526 colonies
1 HR: Test #6 with 424 colonies
On Average: E-coli survivorship is higher after 5 minutes

33. E. COLI RIVER WATER

34. Yeast River Water P-Value: 0.121499
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min
1 HR
P-Value:
Highest Survivorship:
5 minutes : Test #4 at 92 colonies
1 HR: Test #1 at 55 colonies
On Average: Yeast survivorship is higher after 5 minutes

35. YEAST RIVER