The Effects of Laundry Detergent on Microbial Flora Brian Sproule Pittsburgh Central Catholic Grade 9

Laundry Detergent Common household item Alternative to using soap to wash clothes Made up of builders, alkylbenzenesulfonate surfactants, bleaches, and enzymes.

Builders Frequently known as water softeners Made up of: sodium carbonate, complexation agents, soap, and zeolites Zeolites are minerals used as commercial catalysts Most common builder is Sodium Triphosphate Inorganic compound found in modern industrial products

Bleaches Common ingredient found in detergent Used to target stains of vegetable origin Chlorophyll, Anthocyanin Dyes, Tannins, Humic Acids, and Carotenoid Pigments Require Enzymes to aid in removing stains

Enzymes in Detergent Fundamental in the cleaning power of detergent The enzymes remove recalcitrant stains made up of proteins, fats, and carbohydrates Each specific enzyme targets a specific type of stain Fats, Lipases Carbohydrates, Amylases Proteins, Protease

Past Studies Detergent had a negative effect on survivorship of bacteria Varied with current experiment: Used Staph instead of Escherichia coli Powdered detergent Different concentrations

Escherichia coli Extremely prevalent form of bacteria found in a range of environments Gram negative, rod shaped bacteria Reproduces rapidly Mostly harmless or beneficial, but some strands are pathogenic and cause food poisoning Common mammalian intestinal symbiont

Purpose Purpose- Determine the effects of Tide Laundry Detergent on survivorship of Escherichia coli.

Hypotheses Alternative Hypothesis- As concentration of detergent increases, the number of colonies will decrease. Null Hypothesis- The laundry detergent will have no effect on the number of colonies.

Materials Tide Laundry Detergent Micropipettes Sterile Pipet Tips Test Tubes Test Tube Racks Luria Broth Agar Plates (1% Tryptone, 0.5% Yeast Extract, 1% Sodium Chloride) Spreader Bars Ethanol Flame Ethanol Safety Goggles Incubator (37° Celsius) Sharpie Vortexer Escherichia coli Sterile Dilution Fluid (100mM KH2PO, 100mM K2HPO4, 1m NaCl)

Procedure (Liquid Exposure) E. coli was grown until a density of 50 klett spectrophotometer density was reached. This was approximately 8^5 cells/mL. The culture was diluted in sterile dilution fluid to a concentration of approximately 10^5 cells/mL. Pipetted appropriate amounts of Tide Laundry Detergent and Sterile Dilution Fluid into 4 appropriate test tubes Vortexed each test tube to obtain mixed solution Added indicated amount of Escherichia coli to each individual test tube. Solution incubated at room temperature for fifteen minutes

Procedure (Liquid Exposure) Pipetted 0.1mL from each test tube (0.4 mL’s from each tube) on to the LB agar plates. A new pipet was used for the sterile dilution fluid, detergent, and E. coli. Spread solution evenly along the plate by using sterile spreader bars. Each spreader bar was sterilized in an ethanol flame before and after use. A total of 24 liquid exposure plates were done in total Incubated plates at 37° Celsius for 24 hours The number of E. coli colonies were counted and recorded

Liquid Exposure Results P Value: .000213 Significant

Dunnett’s Test Concentration T Value T crit. Value Conclusion 0.01% 1.14 3.1 Not Significant 0.10% 3.6 Significant 1% 4.9

Procedure (Infusions) Stock Solution was made up of 10% detergent and 90% sterile dilution fluid Pipetted 200ul of sterile dilution fluid onto four plates. Pipetted 20ul of the stock solution and 180ul of sterile dilution fluid onto four plates. Pipetted 200ul of pure stock solution onto four plates (Total of 12 Plates) Allowed plates to incubate for one hour at 37° Celsius Pipetted .1ml of the control solution (9.9ml sterile dilution fluid and .1ml E. coli) onto each plate

Procedure (Infusions) Incubated plates for one day at 37° Celsius Plates were taken out and the number of colonies were counted and recorded

Infusions Results P Value: .440534 Not Significant

Conclusion Liquid Exposure Infusions Detergent had a strong antimicrobial effect on the e. coli. Reject null hypothesis for all concentrations Infusions No noticeable antimicrobial effects were found in the infusion process Failed to reject null hypothesis

Limitations Only one form of bacteria was being tested Plating, vortexing, pipetting, exposure times were slightly unsynchronized Limited amounts of concentrations Only one exposure time

Future Experimentation Could test on many different types of bacteria More precise plating and incubating techniques Varying exposure times Synergistic effects with other chemicals Different concentrations of detergent

Works Cited Fiorillo, Doreen E. "The Effect of Detergent on Bacteria." EHow. Demand Media, n.d. Web. 30 Dec. 2015. "Gram Stain Technique." Gram Stain Technique. N.p., n.d. Web. 30 Dec. 2015. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 21 Dec. 2015. Web. 30 Dec. 2015. "E. Coli Bacteria Infection Symptoms, Causes, Treatments." WebMD. WebMD, n.d. Web. 30 Dec. 2015. "E. Coli – the Biotech Bacterium | Biotech Learning Hub." Biotechnology Learning Hub RSS. N.p., n.d. Web. 30 Dec. 2015. "Gram-negative." MedicineNet. N.p., n.d. Web. 30 Dec. 2015 Berlow, Lawrence. "Laundry Detergent." Encyclopedia.com. HighBeam Research, 01 Jan. 1994. Web. 30 Dec. 2015. "Sodium Tripolyphosphate." Sodium Tripolyphosphate. N.p., n.d. Web. 30 Dec. 2015. "Enzymes in Laundry Detergents." Enzymes in Laundry Detergents. N.p., n.d. Web. 30 Dec. 2015. "Zeolites." ASDN. N.p., n.d. Web. 30 Dec. 2015.

ANOVA Liquid Exposure

ANOVA (Infusions)