Jordan Ciccone 9th Grade Pittsburgh Central Catholic Highschool

Jordan Ciccone
9th Grade
Pittsburgh Central Catholic Highschool
*Many different purposes
-Aroma
-Light
-Bug Repelling
*Wax
-Petroleum derived paraffin (C25 H52)
-Beeswax, Stearic Acid, Clear Gels
-Paraffin based candles are the most
popular candles.
*Dies and fragrances
*Wicks
-Twisted fabric braid (usually cotton)
-Most common is flat braid
*Carbon oxides and water
*Paraffin wax candles give off
harmful fumes linked to asthma and
lung cancer.
*Studies show that paraffin wax
candles emit toxic chemicals:
toluene and benzene.
*Both candles used in the experiment
were made from a paraffin based
wax.
* Glade 2 in 1 Scented Candle (113g)
-Paraffin wax, Fragrance, Stabilizer, Dye
* Cutter Vanilla and Lavender Scented Citronella
Candle (311g)
-Paraffin wax, Fragrance, Stabilizer, Dye,
Citronella
*About 10 % of the biomass on the
body is symbionts
*Comprised of all the microorganisms
that reside in or on the human body
*Most species are non-pathogenic,
commensals or mutualists
* Almost 1000 species of bacteria live
in the gut of an average human body.
*Comprised of all microorganisms of
the human flora that live on the
skin.
*1 trillion bacteria live on or in the
skin of an average human.
*Stimulates the skin's immune system
by prevention of colonization by
pathogenic microorganisms.
*Examples of skin dwelling bacteria
-Streptococcus
-Enterococcus
-Neisseria
-Enterobacteriaceae
-Proteus
-Pseudomonas
-Staphylococcus (aureus and
epidermidis)
*Gram positive coccus
*Common surface symbiont in many
mammals (including humans)
*Most forms considered non-pathogenic
*Potentially pathogenic upon systemic entry
*Forms biofilms
*Anaerobic, but grows best in aerobic
conditions
*To assess the effects of candle
fumes on human skin flora
*To test the effects of candle
fumes on the survivorship of
Staphylococcus epidermidis
*Researchers at University of
Southampton found that the addition
of certain oils to candles can kill
bacteria including Staphylococcus.
*Researchers even said it could be as
effective as scrubbing with
disinfectants.
Null Hypothesis:
Prolonged exposure of candle fumes will not
significantly affect the survivorship of the
Staphylococcus e.
Alternate Hypotheses:
1.
Prolonged exposure of candle fumes will
significantly reduce the survivorship of
the Staphylococcus e.
2.
The Citronella candle will have a more
significant affect on the Staphylococcus
e. than the Glade Candle.
* LB Agar plates + media (1% * Cutter Citronella Candle
Tryptone, 0.5% Yeast
Extract, 1% NaCl)
* Staphylococcus e.
* Micro Pipettes + Tips
* Spreader Bars
* Ethanol
* Burner
* Sterile 22mL Test Tubes
* Test Tube Racks
* Vortex
* Burner
* Ethanol
* Glade Candle
* Lighter
* Stopwatch
* Xerox Box
* Tape
* Incubator
* Side Arm Flask
* Klett Spectrophotometer
* Sterile Dilution Fluid
(100mM KH2PO4, 100mM
K2HPO4, 10mM MgSO4, 1mM
NaCl)
1. Staphylococcus e. was grown
overnight in sterile media.
2. A sample of the overnight culture
was added to fresh LB media in a
sterile side arm flask.
3. The culture was incubated at 37°C
until a density of 50 Klett
spectrophotometer units was
reached. This represents a cell
density of approximately 108 cells
per mL.
4. The culture was diluted in sterile
dilution fluid to a concentration of
approximately 103 cells/mL.
5.
After vortexing to evenly suspend the
cells, 100 µL aliquots were removed from
the tube and spread on LB Agar plates.
6. Both of the candles were allowed to burn
for five minutes.
7. Plates were exposed to candle fumes at
varying exposure times: 0 seconds, 1
min, 5 min, and 10 min.
8. The plates were exposed by taping them
to the inside of the lid of a box while the
burning candle sat in the middle of the
box. The box was then closed.
9. The plates were incubated at 37°C for 48
hours.
10.The resulting colonies were counted
visually. Each colony was assumed to
have arisen from one cell.
2,000
P Value;2.89E-10
1,800
P Value;2.14E-18
1,600
Number of
Colonies
1,400
1,200
1,000
0.2133
800
0.1208
600
Glade
Citronella
0.0001
400
200
0
Control
1 Min
5 Min
Exposure Time
10 Min
*T crit- 3.50
*Alpha= 0.05
Group
T Value
Glade 1min13.77 Significant
Citronella 1Min- 12.99 Significant
Glade 5Min9.87 Significant
Citronella 5Min9.58 Significant
Glade 10Min8.50 Significant
Citronella 10Min- 6.82 Significant
1,800
1,600
Number Of Colonies
1,400
LD50: 45s
1,200
LD50: 45s
1,000
Glade
Citronella
800
600
400
200
0
0
1
2
3
4
5
6
7
8
9
Exposure Time (in Minutes)
10
The P-value, 2.89E-10, was less than 0.05.Therefore, the
null hypothesis was rejected.
The P-value, 2.14E-18, was lower than 0.05. Therefore, the null
hypothesis was rejected.
*
*
The null hypothesis was rejected, the
candle fumes did appear to have
significant effects on the survivorship of
the Staphylococcus e.
Both of the alternate hypotheses were
accepted, citronella appeared to reduce
survivorship of the Staphylococcus e.
more than the Glade candle.
*Slightly unsynchronized plating of
bacteria
*Temperature
Exposure Times
Glade
Citronella
0 Minutes
1 Minute
5 Minutes
10 Minutes
13
20
42
45
13
19
30
37
C
C
C
C
*Method of exposure
C
C
C
C
*Test more types of bacteria
*More controlled temperature
*More variables
*More exposure times
*Larger Petri dishes
*Test bacterial growth rate effects
*Test synergistic effects of smoke and
other substances
* http://news.bbc.co.uk/2/hi/health/3813321.stm
* centralcatholichs.com/biology
* http://www.cnn.com/2009/HEALTH/08/21/candles
.air.pollution/index.html
* fire.nist.gov/bfrlpubs/fire05/PDF/f05141.pdf