Page 7 - WCBM JAC 2020 Proceeding Book
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The 8th WCBM Junior Academic Competition, November 7th, 2020
sum of APVAH. According to recent trends, the average economic loss to CCD is estimated to be between
$5,409.6 million and $5,586.3 million with a confidence level of 95%.
2. Identification of Crop Normal Flora.
1) Separation of crop endosymbiotic bacteria from A. mellifera.
The crop was excised from honeybees, and the outer epidermis was sterilized with 90% ethanol. 50 crops were
diluted in 10ml of distilled water with a vortex mixer.
50 ㎕ of the crop solution was spread on nutrient broth and MRS agar plates. The plates were then incubated
at 30℃ for 4 days. Identification of different colonies were based on the form. 12 different colonies were
identified in nutrient agar (NA) and labeled 1-12, and 5 colonies were observed in MRS(a-e).
Figure 1. Crop Bacteria Colonies in NA and MRS
Figure 2. Colonies Observed in NA
Figure 3. Colonies Observed in MRS
2) Bacterial growth in the presence of honey.
Media with 10% honey was prepared by mixing 72 mL of MRS and NB broth with 8ml of honey. 20 ㎕ of
each strain was inoculated to and nutrient broth (NB) and MRS media and the 10% honey NB and MRS media.
After being vortexed, they were cultured at 30°C for 4 days. Absorbance of 1mL of the cultured media at 600nm
was observed using a spectrophotometer.
In the NB strains, all strains except 1, 6, and 7 showed increased growth. Strain 4 increased as much as by
691%. 1, 6, and 7, however, showed steady growths. 1 and 7 showed menial increases in their growths, and strain
6 decreased slightly by 0.1. This was negligible compared to the others. In the MRS strains, only strain a showed
a significant increase of 226%. The others showed constant growth independent to the presence of honey. The
results showed that all 17 crop bacteria strains can survive in the presence of honey, and strains 1, 6, 7, b, c, d,
and e is not affected by its presence.
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