Lab Experiment III. Antibiotic Properties of Bee Venom
Melittin is the main component (40–60% of the dry weight) and the major pain producing substance of honey bee (Apis mellifera) venom. Melittin is reported to hold antibiotic properties with higher efficiency against gram positive bacteria compared to gram negative bacteria. The antibacterial properties of bee venom was tested against gram negative and positive bacteria in four different concentrations (45 μg/mL; 35 μg/mL; 25 μg/mL;
To determine if bee venom has antibacterial properties and if different concentrations affect different types of bacteria (gram negative or gram positive).
- Does bee venom have antibiotic properties?
- Is bee venom more antibacterially active against gram negative or gram positive bacteria?
- Which is the most effective concentration of bee venom against each type of bacteria?
Materials and Methods
- 18 petri dishes - Distilled water - Agar - Sharpie - Hot Plate - Cryogenic vials - Bee venom - 72 paper discs - Gram negative bacteria - Gram positive bacteria - Micropipette - Plastic tips - Incubator - Colorimeter - Pipette Pump - Disposable Pipettes
18 petri dishes were separated into four labeled sections with a sharpie; half were labeled gram positive and the other, gram negative.
Agar was poured into the mixture.
While it was cooling, four different concentrations of bee venom were prepared with a micropipette (reference table one).
Table One: Ratios of Concentrated Mixtures of Diluted Bee Venom
|Mixture||Concentration||Amount Bee Venom (μL)||Amount H20 (μL)|
After about fifteen minutes, once the agar cooled, four paper discs were placed in each petri dish, one disc per section. One μL of each concentration was carefully placed into it’s labeled section. Section one referencing the 45 μg/mL concentration, two referring to the 35 μg/mL concentrations, three to 25 μg/mL, and section four refers to the 0 μg/mL concentration. Once a microliter of each concentration was dropped onto each of the correlative discs, the petri dishes were placed into a microbiological incubator and left to sit until the next day.
After the petri dishes incubated, students took pictures of mostly every dish. These pictures were used to find the zones of inhibition of each paper disc. Each student measured to the nearest half millimeter. It was found that the average zone of inhibition of the gram positive bacteria was 14.972 millimeters, and the average zone of inhibition of the gram negative bacteria was 16.64 millimeters. This means that the treated paper discs withheld in gram negative bacteria had a larger ring of no bacterial growth. The most beneficial concentration to bee venom was also found, determined by an average. The most effective concentration was section three, 25 μg/mL, with average of 19.44 mm in gram positive bacteria and 17.73 mm in gram negative bacteria.
Table Two: Average Distance of Antibacterial Effectiveness in Each Concentration (mm)
|Section||Concentration||Gram Positive Zone of Inhibition||Gram Negative Zone of Inhibition|
|1||45 μg/mL||15.79 mm||14.84 mm|
|2||35 μg/mL||14.39 mm||17.72 mm|
|3||25 μg/mL||19.44 mm||17.73 mm|
|4||0 μg/mL||10.28 mm||16.76 mm|
Overall this answers both questions previously stated: Our experiment provided an opposing outcome than that of melittin, bee venom is more active against gram negative bacteria; also throughout both bacterias, 25 μg/mL concentration was proven the most effective. This shows that bee venom does have antibacterial properties, and although better against some than others, numerous bee venom concentrations have the possibility to be used against difference ailments.