Red Acid Dye Effects of Microbial
Life
Ryan Kramer
Grade 11
Pittsburgh Central Catholic
Problem
• Water systems are polluted with:
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Antibiotics
Pharmaceuticals (Estrogen, etc.)
Mercury
Sulfur
Sewage
Fertilizers
Organics
Cleaning projects
Dyes and other colored agents
Dye Effects on Water
• Studies have shown that dyes add unwanted
colors and toxins to water that effect microbial
life and algal photosynthetic rates.
Euglena Gracilis
• Unicellular organism from the Protista
Kingdom.
• Both autotrophic and heterotrophic.
• Found in fresh and salt water.
• Reproduce rapidly.
• Absorbs light readily.
Acid Dye
• Used by companies to color clothing, textiles, ect.
• Researchers claim they’re non toxic and have no
harmful effect on aquatic life.
• Billions of gallons dumped changed
photosynthetic rates and alter PH harming
aquatic life.
• Modern chemistry still can’t prevent all dye
problems
• Sudan I crisis in the UK when a carcinogenic dye got
in over 400 super market items.
Food Coloring
• Studies have shown colors affect taste
• For this reason companies add colors to enhance dining
experience
• It is a non-toxic dye.
• Chosen because
• Its non-toxic
• Easy to obtain
• Will test if color alone will effect algal
growth
Spectrophotometer
• Device measuring light intensity or
wavelengths of light
• Used for measuring light absorption
• Measures the light absorption of the algae
• More absorption means more algae
• Wavelength: 430nm
Purpose
• To determine if dyes have an
effect on the growth of the
Euglena Gracilis.
Hypothesis
• Null Hypotheses: Adding color will not
have a significant effect on algal growth.
• Alternative Hypotheses: Adding color
will have a significant effect on algal
growth.
Materials
• Science Kit Educator
Spectrophotometer
• 80 13x100 mm
borosilicate culture test
tubes
• Red food coloring
• Micropipette
• Test tube rack
• Pipette tips
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Red Acid Dye
Euglena Gracilis
Microscope
Hemocytometer
Spring Water
Soil Water
Procedure
• Stock solutions of food coloring and dye were
generated.
Spring H2O
Soil H2O
Euglena
AD/FC
0%
2mL
1mL
2mL
0mL
1%
1.90mL
1mL
2mL
10uM
5%
1.50mL
1mL
2mL
50uM
Procedure
• The spectrophotometer was blanked and
absorbance readings were taken.
• Absorbance readings for each tube were taken
at 430 nm every day for two weeks.
• After two weeks a cell count was taken with a
hemocytometer at 100 times magnification to
check if the cells were alive after 2 weeks.
Euglena Absorbance
1.6
1.55
P Value: 6.064x10E-29
Abs. at 430 nm
1.5
1.45
Control
1% FC
1.4
5% FC
1.35
1% AD
5% AD
1.3
1.25
1.2
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9 Day 10 Day 11 Day 12 Day 13 Day 14
Extent of Time
Dunnett’s Test
T Crit: 3.48
Variable Group
T Value
Interpretation
1 % FC
3.51
Significant
5 % FC
5.43
Significant
1% AD
5.51
Significant
5% AD
10.63
Significant
Euglena Cell Counts After 14 Days
45000
40000
P Value: 4.43E-12
Number of Cells
35000
30000
25000
20000
15000
10000
5000
0
Control
1% FC
5% FC
Variable Group
1% AD
5% AD
Dunnett’s Test
T Crit: 3.48
Variable Group
T Value
Interpretation
1 % FC
3.57
Significant
5 % FC
5.289
Significant
1% AD
6.289
Significant
5% AD
11.889
Significant
Conclusion
• The null hypothesis was rejected for all four
groups in the absorbance and cell count tests.
• This means that the algae survivorship was
significantly effected by the red colored dyes.
• The most likely explanation for the decline in
algal growth was the added color effected
photosynthetic rates.
Limits and Extension
• Limits
• The test tubes may have receive differing amounts of
sun light which could change photosynthesis.
• Only one type of algae was used in this experiment.
• Extensions
• Test more colors of dye.
• Introduce a compound to break down the dye to see if
dye break down affect the algal growth.
References
• K.Suthagar. POLLUTION_CONTROL_IN_DYE_INDUSTRY-_2204-09. National Centre for Catalysis Research. PPT.
• "Water Pollution." MBGnet. Web. 05 Nov. 2011.
<http://www.mbgnet.net/fresh/pollute.htm>.
• "BBC NEWS | Health | Food Recalled in Cancer Dye Scare."
BBC News - Home. Web. 05 Nov. 2011.
<http://news.bbc.co.uk/2/hi/health/4277677.stm>.
• "Acid Dye." Wikipedia, the Free Encyclopedia. Web. 05 Nov.
2011. <http://en.wikipedia.org/wiki/Acid_dye>.
• "Food Coloring." Wikipedia, the Free Encyclopedia. Web. 06
Nov. 2011. <http://en.wikipedia.org/wiki/Food_coloring>.
• http://www.emc.maricopa.edu/faculty/farabee/biobk/biob
ookps.html