Jordan Ciccone 9 th Grade Pittsburgh Central Catholic Highschool

Transcription

1 Jordan Ciccone 9 th Grade Pittsburgh Central Catholic Highschool

2 *Many different purposes -Aroma -Light -Bug Repelling

3 *Wax -Petroleum derived paraffin (C 25 H 52 ) -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

4 *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.

5 *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

6 *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.

7 *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.

8 *Examples of skin dwelling bacteria -Streptococcus -Enterococcus -Neisseria -Enterobacteriaceae -Proteus -Pseudomonas -Staphylococcus (aureus and epidermidis)

9 *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

10 *To assess the effects of candle fumes on human skin flora *To test the effects of candle fumes on the survivorship of Staphylococcus epidermidis

11 *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.

12 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.

13 * LB Agar plates + media (1% 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 *Cutter Citronella Candle *Lighter *Stopwatch *Xerox Box *Tape *Incubator *Side Arm Flask * Klett Spectrophotometer *Sterile Dilution Fluid (100mM KH2PO4, 100mM K2HPO4, 10mM MgSO4, 1mM NaCl)

14 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 10 8 cells per ml. 4. The culture was diluted in sterile dilution fluid to a concentration of approximately 10 3 cells/ml.

15 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.

16 Number of Colonies 2,000 1,800 1,600 1,400 1,200 1, P Value;2.89E-10 P Value;2.14E-18 Glade Citronella Control 1 Min 5 Min 10 Min Exposure Time

17 *T crit *Alpha= 0.05 Group T Value Glade 1min Significant Citronella 1Min Significant Glade 5Min Significant Citronella 5Min Significant Glade 10Min Significant Citronella 10Min Significant

18 Number Of Colonies 1,800 1,600 1,400 1,200 1, LD50: 45s LD50: 45s Glade Citronella Exposure Time (in Minutes)

19 The P-value, 2.89E-10, was less than 0.05.Therefore, the null hypothesis was rejected.

20 The P-value, 2.14E-18, was lower than Therefore, the null hypothesis was rejected.

21 * 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.

22 *Slightly unsynchronized plating of bacteria *Temperature Exposure Times Glade Citronella 0 Minutes 1 Minute 5 Minutes 10 Minutes 13 C 20 C 42 C 45 C *Method of exposure 13 C 19 C 30 C 37 C

23 *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

24 * *centralcatholichs.com/biology * *fire.nist.gov/bfrlpubs/fire05/pdf/f05141.pdf