Water Source Influence of Microbial Survivorship
By Zachary PoppishGrade 9Central Catholic High School Pittsburgh
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?
Common Creek and River Pollutants
Detergents
Fertilizers
Animal waste
Automotive products
Pesticides
Can runoff products aid or hinder microbial growth?
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
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
Microbes Tested
Escherichia coli (E.coli)
Saccharomyces cerevisiae (Yeast)
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.
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
Materials used1. 72 YEPD agar plates(1% yeast extract, 2%
peptide, and 2% glucose)2. Sterile pipette tips3. Micropipettes4. Vortex5. Incubator 6. Spreading turntable7. Spreader bar8. Escherichia coli (e.coli)9. Saccharomyces cerevisiae (yeast)
10. Sample water from Deer Creek11. Sample water from the Allegheny
River12. Sample of SDF (100mM KH2PO4,
100mM K2HPO4, 10mM MgSO4, and 1mM NaCl)
Procedure
1. Collected samples from local creek and river in a sterile container2. Sterilized the 2 water samples using 0.2 micron syringe filter3. The waters were transferred to sterile 15 mL conical tubes4. The yeast and E. coli were diluted from their stocks to a tube with
a concentration of 10^5 cells per mL5. 100 microliter samples of the microbes were transferred into the
water samples6. The tubes were incubated at room temperature for 5 min and 1 hr7. After 5 and 60 minutes 100 microliters of the mixtures were
transferred to YEPD agar plates.8. Plates were incubated (yeast= 37C for 48hr and E. coli 37C for
24hr)9. The resulting colonies were counted
Variables
Independent: Exposure Time/Water sample/Microbe used
Dependent: Amount of colonies
Control: Sterilized water
Hypothesis
Alternative: The natural water bodies will reduce the microbial survivorship.
Null: The waters samples will not significantly hinder the microbes survivorship.
E. coli average colonies
P-value:5 min: 0.74706160 min: 0.002009
Dunnett’s Test-E. coli
F-Crit:3.885 Creek River
5 min Unable to dunnett’s test because data was not significant
Unable to dunnett’s test because data was not significant
1 hr -8.026-Significant -1.538-insignificant
Yeast Average Colonies
P-value:5 min: .0.00123360 min: .0.587849
P-value:5 min: 0.00011660 min: 0.829171
Dunnett’s Test-Yeast
F-crit:3.885 Creek River
5 min 9.937-significant .177-insignificant
1 hr Unable to dunnett’s test because data was not significant
Unable to dunnett’s test because data was not significant
Percent Survivorship
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.
Reason
● Different pH values?● Different minerals and other ions?● Different types of pollutants?
Limitations
1. Tested only one river and one creek
2. Only 2 time periods tested3. Only survivorship and no other health parameters4. Unknown composition of waters
5. Water was taken from river and creek during winter months
Improvements
1. Test multiple creeks and rivers to test for pollutants/different areas (RESIDENTIAL, AGRICULTURAL AND URBAN)
2. Do a chemical analysis of the waters
3. Test during different times of the year/temperatures
4. Test lakes and ponds for pollutants
Works cited
https://about-ecoli.com/http://www.waterencyclopedia.com/La-Mi/Microbes-in-Lakes-and-Streams.html https://www.lenntech.com/rivers-pollution-qualityhttps://people.uwec.edu/piercech/hml/Common%20sources%20of%20water%20pollution.htmhttps://redstaryeast.com/science-yeast/what-is-yeast/ https://wiki.yeastgenome.org/index.php/What_are_yeast%3F
Overall Results:I 5 MINUTES 1 HOUR
E-coli
Sterilized Water 435 421
Creek Water 326 239
River Water 414 391
Yeast
Sterilized Water 62 42
Creek Water 216 38
River Water 64 45
● E-coli higher survivorship in 5 min versus 1 hour
● Reason: Less exposure to chemicals in water
E-Coli: SDF
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 460 452 440 404 432 424 435
1 HR 408 420 400 451 384 464 421
P-Value: 0.367479668
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
E. COLI SDF (Sterilized Water)
Yeast: SDF
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 87 35 70 55 54 69 62
1 HR 39 46 34 44 34 52 42
P-Value: 0.027479
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
YEAST SDF (Sterilized Water)
E-Coli: Creek Water
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 240 101 540 344 410 320 326
1 HR 400 296 248 136 288 67 239
P-Value: 0.293216
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
E. COLI CREEK WATER
Yeast: Creek Water
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 208 216 424 176 104 168 216
1 HR 28 60 38 43 47 9 38
P-Value: 0.002736
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
YEAST CREEK WATER
E-Coli: River Water
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 308 526 368 524 364 392 414
1 HR 408 400 432 320 360 424 391
P-Value: 0.586029
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
E. COLI RIVER WATER
Yeast River Water
Time Test #1 Test #2 Test #3 Test #4 Test #5 Test #6 Average
5 Min 33 51 84 92 38 88 64
1 HR 55 32 50 48 35 49 45
P-Value: 0.121499
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
YEAST RIVER