Experimental Report on Antibacterial Properties of Lemon, Apple, and Strawberry Plant Extract
1. Introduction
The increasing prevalence of antibiotic-resistant bacteria has necessitated the exploration of alternative antibacterial agents, particularly from natural sources. Fruits such as lemons, apples, and strawberries are not only rich in vitamins and antioxidants but are also suggested to possess antibacterial properties due to their phytochemical constituents. This study explores the antibacterial activities of plant extracts from lemon, apple, and strawberry against common pathogenic bacteria.
2. Aim
To investigate and compare the antibacterial properties of lemon, apple, and strawberry plant extracts against selected bacterial strains.
3. Objectives
- To prepare extracts from lemon, apple, and strawberry.
- To evaluate the antibacterial activity of these extracts against specific bacterial strains (E. coli and Staphylococcus aureus).
- To compare the effectiveness of each fruit extract in inhibiting bacterial growth.
4. Research Questions
- Do lemon, apple, and strawberry plant extracts exhibit antibacterial activity against E. coli and Staphylococcus aureus?
- Which of the three fruit extracts demonstrates the strongest antibacterial effect?
- How does the concentration of each extract affect its antibacterial properties?
5. Hypothesis
It is hypothesized that lemon extract will exhibit the strongest antibacterial properties followed by strawberry and then apple extracts due to its high citric acid content and other phenolic compounds.
6. Materials
- Fresh lemons, apples, and strawberries
- Ethanol (95% for extraction)
- Nutrient agar plates
- Bacterial cultures (E. coli and Staphylococcus aureus)
- Sterile swabs
- Petri dishes
- Incubator
- Measuring cylinders
- Mortar and pestle
- Filter paper
- Pipettes
- Sterile water
7. Procedure
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Preparation of Plant Extracts:
- Collect fresh fruits: lemons, apples, and strawberries.
- Wash and cut them into small pieces.
- Blend each fruit with a small amount of ethanol (1:1 ratio) to prepare the extract.
- Filter the mixture through filter paper to obtain the clear extract.
- Label and store the extracts in clean containers in a refrigerator.
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Bacterial Culture Preparation:
- Inoculate nutrient broth with E. coli and Staphylococcus aureus and incubate overnight at 37°C.
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Antibacterial Testing:
- Prepare nutrient agar plates by pouring agar into sterile Petri dishes and letting it solidify.
- Using sterile swabs, inoculate the surface of the agar plates with the bacterial cultures evenly.
- Create wells on the agar plates using a sterile cork borer.
- Add 50 µL of each plant extract into the wells and control wells with ethanol alone.
- Incubate the plates at 37°C for 24 hours.
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Observation:
- After incubation, measure the diameter of the inhibition zones surrounding each well using a ruler.
8. Results
The diameters of inhibition zones for E. coli and Staphylococcus aureus were measured and recorded as follows:
| Plant Extract | E. coli Inhibition Zone (mm) | Staphylococcus aureus Inhibition Zone (mm) | |----------------|-------------------------------|--------------------------------------------| | Lemon | 15 | 18 | | Apple | 10 | 12 | | Strawberry | 12 | 14 | | Ethanol (Control) | 0 | 0 |
9. Discussion
The results indicate that all three fruit extracts demonstrated antibacterial activity against E. coli and Staphylococcus aureus, with lemon extract exhibiting the strongest inhibitory effect. This can be attributed to the presence of citric acid and various antioxidants that disrupt bacterial cell membranes or inhibit essential enzymatic processes. The apple extract, while less effective, still produced measurable zones of inhibition, suggesting the presence of compounds with antibacterial properties, albeit not as potent as those found in lemon and strawberry extracts. The control showed no antibacterial activity, confirming that the extracts were responsible for the observed effects.
10. Conclusion and Recommendations
This study provides evidence for the antibacterial properties of lemon, apple, and strawberry extracts, with lemon extract showing the highest activity. Further research is recommended to isolate and identify specific compounds within these fruits responsible for the antibacterial effects. Additionally, future studies could explore the effects of different extraction methods and concentrations on antibacterial efficacy to enhance practical applications in food preservation and medicine.