David Stragar
Pittsburgh Central Catholic
PJAS 2010
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Most algal deaths result from salt runoff.
During winter, road salt runoff escalates.
Many attempts have been made to create a
safe ice melt salt.
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Is part of the water cycle and describes the
water that flows over a land surface.
◦ Materials that are transported on surface runoff are
salt, fertilizers, petroleum, pesticides, herbicides,
pharmaceuticals, hygiene products, etc.
◦ Water source runoff pollution?
◦ Mouthwash runoff?
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Listerine is made to kill
bacteria in the oral cavity
that cause plaque buildup
and bad breath.
Ingredients: water, menthol,
methyl salicylate, eucalyptol,
thymol, alcohol, benzoic
acid, sorbitol, sodium
benzoate
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Sodium chloride is the
salt most responsible for
the salinity of the ocean.
Aside from road de-icing,
salt can have many other
uses, from cooking,
manufacturing pulp and
paper, to setting dyes in
textiles and fabric.
A more commonly
known form of NaCl
known as table salt
This is a high resolution
picture of Halite
Used as a bio indicator for
aquatic environments
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Base of aquatic food
chain
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Common algal like protist
Extremely tolerant of many habitats
Capable of survival in both salt and water
environments
Partial heterotrophs can attain food through
endocytosis and photosynthesis
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Device that measures light intensity or
wavelengths of light
Used for measuring light absorption
Measures the light absorption of the algae
◦ More absorption = more algae
◦ Wavelength: 430nm
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Effects of road salt on the environment were
first noticed in the 1950s
Along the Minnesota highway, trees within a
3.4 mile radius of the road were showing
indications of salt related death.
At this same time period the New Hampshire
government reported the death and removal
of about 14,000 trees due to salt related
problems.
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To determine if mouthwash or NaCl have any
significant effect on algae growth and survival.
Determine any synergistic effects of these
variables
Null hypothesis: Mouthwash and NaCl will
not effect Euglena growth.
Alternative: Mouthwash and NaCl will
effect Euglena growth.
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Euglena gracilis algae
NaCl stock concentration of 10%
Cool Mint Listerine Mouthwash
37 Test tubes
Test tube rack
Spectrophotometer
Grow light source
Soil water
Macro pipette and tips
Micropipette and tips
Spring water
Notebook
Calculator
1. Fill 36 Test tubes as follows
0% NaCl
1% NaCl
5% NaCl
0 Mouthwash Concentration
.1 Mouthwash Concentration
.01 Mouthwash Concentration
1 mL Soil Water
1 mL Soil Water
1 mL Soil Water
1 mL Algae
1 mL Algae
1 mL Algae
3 mL Spring Water
2.7 mL Spring Water
2.97 mL Spring water
0 mL Mouthwash
0.3 mL Mouthwash
0.03 mL Mouthwash
5 mL Total Volume
5 mL Total Volume
5 mL Total Volume
1 mL Soil Water
1 mL Soil Water
1 mL Soil Water
1 mL Algae
1 mL Algae
1 mL Algae
2.97 mL Spring Water
2.67 mL Spring Water
2.94 mL Spring Water
0.03 mL NaCl
0.03 mL NaCl
0.03 mL NaCl
0 mL Mouthwash
0.3 mL Mouthwash
0.03 mL Mouthwash
5 mL Total Volume
5 mL Total Volume
5 mL Total Volume
1 mL Soil Water
1 mL Soil Water
1 mL Soil Water
1 mL Algae
1 mL Algae
1 mL Algae
2.55 mL Spring Water
2.25 mL Spring Water
2.520 mL Spring Water
0.45 mL NaCl
0.45 mL NaCl
0.45 mL NaCl
0 mL Mouthwash
0.3 mL Mouthwash
0.03 mL Mouthwash
1. Record all absorbance readings at
430 nm for all tubes.
 2. Place test tube rack under grow
light.
 3. Record absorbance on days 1, 3, 5,
7, and 9.
 4. Spring water was added to the
tubes to replace water lost due to
evaporation
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Limitations
◦ Algae was not kept at the same temperature each
day.
◦ Weather variations could have slightly effected data.
◦ Algal cultures might not have been in optimal
health
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Extensions
◦ Algal health- the study will be repeated using a
fresh culture and a longer period of observation
◦ Different light fixtures and sources
◦ Larger sample size
Mouthwash and NaCl Effects on Algal Growth
0.6
Absorbance
430 nm
0.5
0.4
0%
0.3
1%
5%
0.2
0.1
0
Day 1
Day 3
Day 5
Day
Day 7
Day 9
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"Evaluating Support for the Current Classification of Eukaryotic
Diversity". PLoS Genet. 2 (12): e220.
doi:10.1371/journal.pgen.0020220. PMID 17194223.
p://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez
&artid=1713255.
alga, algae". Webster's Third New International Dictionary of the
English Language Unabridged with Seven Language Dictionary. 1.
Encyclopedia Britannica
"De-icer damaging thousands of trees on mountain passes". The
Seattle Times (19 March 2008). Retrieved on 18 March, 2008.
Aliphatic Chains of Esterified Lipids in Isolated eyesptos of Euglena
gracilis var. bacillaris1
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www.oercommons.org/courses/algae-experiments
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en.wikipedia.org/wiki/Spectrophotometer
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en.wikipedia.org/wiki/NaCl
hamptonroads.com/2008/01/odu-experiment-turningsewage-algaebased-biodiesel-flourishing
www.dow.com/productsafety/finder/cacl