The Antibacterial Properties of Honey Megan Wasson Oakland Catholic High School

Problem Can honey significantly inhibit the survival of bacteria colonies?

Motivation and Background Observations of healing properties of honey have been noted by many ancient scientists and scholars including Hippocrates. Using a natural substance such as honey for antimicrobial purposes offers a holistic solution for modern medicine. Majority of raw honeys have the enzyme glucose oxidase which produces hydrogen peroxide that has definite antibacterial properties. Manuka Honey is noted in the scientific literature for its antibacterial properties but does not have the enzyme glucose oxidase.

Purpose To observe the effects of various honey solutions on E. coli colonies-selected bacteria medium. Specifically, to investigate if the honey solutions will hinder the survival rate of the E. coli colonies.

Hypothesis The various honey solutions will inhibit the survival rate of E. coli colonies. Null Hypothesis The various honey solutions will not significantly impact the survival rate of E. coli colonies.

Materials LB (luria broth) LB agar plates DH5- alpha E. coli Spreader bar Turn table Ethanol Sterile test tubes Micropipettes and tips Incubator Sterile water Organic Honeydew Honey Bunsen burner Hot plate Stirrer Bar Vortex Microsoft Excel

Experimental Thrusts Principal Experiment: Collect data to confirm or negate hypothesis of honey impacting E. coli colony survival rate. Additional Experiment: Conduct test to prove that the honey was absorbed into the agar plate and to further confirm or negate the hypothesis.

Procedure for Principal Experiment 250 mL of honey was heated to reduce the high viscosity. Designated amount of water, honey, and E. coli was micropipetted into a tube which was vortexed. SolutionmL of sterile water mL of honeymL of E. coli 0% (control) % % %

Procedure for Principal Experiment (Continued) 0.1 mL of each solution was micropipetted onto a designated agar plate Total of eight plates for each solution Solution was spread on plate with spreader bar and turn table Plates were incubated at 37ºC overnight

Principal Experiment Results: Average Number of E. coli Colonies vs. Honey Solution P-value= 7.69x10^-3

Principal Experiment Results: Dunnett Test Results Honey SolutionT- ValueInterpretation 10%1.686Insignificant 25%2.925Significant 50%3.471Significant T-Critical=2.88

Procedure for Additional Experiment: Direct Exposure to Heat and Cold Conducted to ensure honey was inside agar. Specific steps included the following: 1.1 mL of pure honey was pipetted on agar plate plates were placed in incubator at 37ºC for 30 minutes and 12 plates were placed outside in 0ºC for 30 minutes mL of 0%, 10%, or 50% solution was placed and spread on designated dish. –Total of 4 dishes for each solution for each temperature 4.Dishes were placed in an incubator at 37ºC overnight.

Additional Experiment Results: Direct Exposure to Heat: Average Amount of E. coli Colonies vs. Honey Solution P-Value= 1.74x10^-2

Additional Experiment Results: Direct Exposure to Cold: Average Amount of E. coli Colonies vs. Honey Solution P-Value=2.13x10^-2

Conclusions Hypothesis was supported and null hypothesis was rejected as the various honey solutions significantly inhibited the survival rate of E. coli colonies.

Limitations Honey was extremely viscous and pipettes were not designed to distribute precise and accurate amounts of liquid. Some plates did not receive immediate transport to the incubator which provides the necessary environment to for the growth of E. coli.

Future Experimentation Test the survival rate of other bacteria with honey solutions. Compare the effects of honeys with glucose oxidase enzyme and the effects of Manuka honey on bacteria. Create mixtures of honey and vitamins and apply the mixtures to bacteria and observe its survival rate.

Active Manuka Honey Association. AMHA Web. 3 Oct Cimolai, Nevio. Sweet Success? Honey as a Topical Wound Dressing. BC Medical Journal. 2 March Web. 28 Sept Knox, Angie. Harnessing Honey's Healing Power. BBC. 4 June Web. 30 Sept Sivasubramaniam, Lakshmi. Medicianl Properties of Liquid Gold: Honey. Pharmainfo.net. 16 Dec Web. 28 Sept Slater, Michael. Does honey have healing benefits? MSN. 27 Nov Web. 30 Sept A special thank you to Mr. Krotec and Central Catholic High School for help and use of facilities Sources and Acknowledgements