Scientific Poster

1
Evaluation of the Antibacterial Activity of
Fortunella margarita

• Results
• Aqueous and ethanolic mesocarp extracts inhibit
  E. coli growth (Figure 2).
• The minimum inhibitory concentration of aqueous
  mesocarp extract is 5.63 µg/mL against E. coli.
• The minimum bactericidal concentration of aqueous
  mesocarp extract is 45.0 µg/mL against E. coli.
• F. margarita juice has a pH of 3
• F. margarita does not produce lysozyme (Figure
  3).
• Bactericidal properties of aqueous mesocarp
  extract were not destroyed by heat.
• Mesocarp inhibited the generation time of E. coli
  for over an hour (Figure 4).
• The aqueous mesocarp extract decreased the growth
  of E. coli on raw spinach (Figure 5).

• Methods
• Extract Preparation
• Fruits and leaves were from an organically-grown
  garden plant.
• Leaf, exocarp, and mesocarp extracts were
  prepared by grinding 1.0 g plant tissue in 4 mL
  solvent in a mortar. Solvents distilled water
  and 85 ethanol. Tissue extracts were filtered
  through 2 layers of cheesecloth and filter
  sterilize through 0.45 µm filter.
• Well Diffusion Assay
• Holes (4-mm) were punched in the nutrient agar
  and inoculated plates with test bacteria.
  (Escherichia coli and Staphylococcus aureus)
• Wells were filled with 50 µL extract or solvent.
• Incubate plates at 37C for 24 to 48 hr.
• Minimal Inhibitory/Bactericidal Concentration
• 2-fold serial dilution from 180. µg/mL to .0879
  µg/mL of aqueous mesocarp extract were made in
  nutrient broth
• Dilutions were inoculated with E. coli and
  incubated at 37C for 24 hr.
• Dilutions with no growth were subcultured in
  nutrient broth.
• Determination of Protein Assay
• Aqueous mesocarp extract was heated to 56C for
  30 min.
• The well diffusion assay against E. coli was
  repeated with the heated and unheated extract.
• Determination of Lysozyme Activity
• A 10-1 dilution of kumquat juice was prepared in
  lysozyme buffer and inoculated with lysozyme
  substrate (Micrococcus luteus).
• Egg-white lysozyme was used as the control.
• Absorbance was recorded at 540 nm for 20 min.

Figure 1. Fortunella margarita, kumquat, is in
the Rutaceae family. This plant is native to
Southeast Asia, and the fruit grows to 5 cm long.